straight.el: An Emacs Lisp repository from dajva

straight.el: next-generation, purely functional package manager for the Emacs hacker.

Please check out the FAQ and news :)

Features
Guiding principles
Getting started
- Debugging
Conceptual overview
Comparison to other package managers
User manual
Developer manual
Trivia
- Comments and docstrings
Contributing
FAQ
News

Features

Install Emacs packages listed on MELPA, GNU ELPA, or Emacsmirror, or provide your own recipes.
Packages are cloned as Git (or other) repositories, not as opaque tarballs.
Make changes to a package simply by editing its source code, no additional steps required. Contribute upstream just by pushing your changes.
Powerful interactive workflows (with popups à la Magit) for performing bulk maintenance on the Git repositories for your packages.
Save and load version lockfiles that ensure 100% reproducibility for your Emacs configuration. Package state is defined entirely by your init-file and (optional) lockfile, with no extra persistent data floating around.
Specify package descriptions using a powerful recipe format that supports everything from MELPA recipes and more.
use-package integration.
Modular: you can install your packages manually and straight.el will load them for you. Or you can also have straight.el install your packages, while you provide the recipes explicitly. Or straight.el can also fetch recipes, if you want. Bulk repository management and package updates are also optional.
Extensible APIs to add new recipe sources and version-control backends.
The cleanest source code you've ever seen. 45% of straight.el is comments and docstrings.

Guiding principles

Init-file and version lockfiles as the sole source of truth. No persistent state kept elsewhere.
100% reproducible package management, accounting for changes in packages, recipe repositories, configuration, and the package manager itself.
No support whatsoever for package.el.
Edit packages by editing their code, no extra steps required. Allow for manual version control operations.
Compatibility with MELPA, GNU ELPA, and Emacsmirror.
Trivial to quickly try out a package without permanently installing it.
Good for reproducing an issue with emacs -Q.

Getting started

Note: straight.el supports a minimum version of Emacs 24.4, and works on macOS, Windows, and most flavors of Linux.

First, place the following bootstrap code in your init-file:

(defvar bootstrap-version)
(let ((bootstrap-file
       (expand-file-name "straight/repos/straight.el/bootstrap.el" user-emacs-directory))
      (bootstrap-version 5))
  (unless (file-exists-p bootstrap-file)
    (with-current-buffer
        (url-retrieve-synchronously
         "https://raw.githubusercontent.com/raxod502/straight.el/develop/install.el"
         'silent 'inhibit-cookies)
      (goto-char (point-max))
      (eval-print-last-sexp)))
  (load bootstrap-file nil 'nomessage))

Here are some variables you may be interested in (some of them must be set before the bootstrap code runs, if they might affect how straight.el itself is loaded):

straight-repository-branch -- to get the latest version of straight.el from the develop branch, rather than the default master which is updated less frequently but which is ostensibly more stable.
straight-check-for-modifications -- to configure an alternate way for straight.el to check for modifications made to package source code, rather than the default (which is 100% reliable, but has a minor cost to startup time).
straight-use-package-by-default -- if you use use-package, then this makes each use-package form also invoke straight.el to install the package, unless otherwise specified.
straight-vc-git-default-protocol -- by default, straight.el clones over HTTPS. If you need packages from private Git repositories in your configuration, then you might want to use SSH instead.

You should remove any code that relates to package.el; for example, references to package-initialize, package-archives, and (if you're using use-package) :ensure or use-package-always-ensure. While it is technically possible to use both package.el and straight.el at the same time, there is no real reason to, and it might result in oddities like packages getting loaded more than once.

Debugging

On macOS, you may receive an error:

Could not create connection to raw.githubusercontent.com:443

There are two ways to solve this problem. One way is to install a version of Emacs that is linked with GnuTLS. The Homebrew formula for Emacs was recently updated to link with GnuTLS by default, so you need only do this:

$ brew upgrade emacs

The other way is to let Emacs use certificates provided by LibreSSL, which you can do by running this command:

$ brew install gnutls libressl

And adding this to your init-file, before the bootstrap snippet:

(with-eval-after-load 'gnutls
  (add-to-list 'gnutls-trustfiles "/usr/local/etc/libressl/cert.pem"))

Install packages

Out of the box, you can install any package listed on MELPA, GNU ELPA, or Emacsmirror, which is to say any package in existence. (Although MELPA is used as a package listing, packages are installed by cloning their Git repositories rather than by downloading tarballs like package.el does.) To install a package temporarily (until you restart Emacs), run M-x straight-use-package and select the package you want. To install a package permanently, place a call to straight-use-package in your init-file, like:

(straight-use-package 'el-patch)

Note that installing a package will activate all of its autoloads, but it will not actually require the features provided by the package. This means that you might need to use require or autoload for some antiquated packages that do not properly declare their autoloads.

To learn more, see the documentation on the package lifecycle.

But what about my fork of (obscure .el package)?

Instead of passing just a package name to straight-use-package, you can pass a list ("recipe"). You can see the default recipe for any given package by running M-x straight-get-recipe. For example, the recipe for el-patch is:

(el-patch :type git :host github :repo "raxod502/el-patch")

So, if you have forked el-patch and you want to use your fork instead of the upstream, do:

(straight-use-package
 '(el-patch :type git :host github :repo "your-name/el-patch"))

In fact, straight.el has explicit support for using a forked package, since this is so common:

(straight-use-package
 '(el-patch :type git :host github :repo "raxod502/el-patch"
            :fork (:host github
                   :repo "your-name/el-patch")))

You may also omit the :type git if you leave straight-default-vc at its default value of git.

To learn more, see the documentation on the recipe format.

Integration with `use-package`

use-package is a macro that provides convenient syntactic sugar for many common tasks related to installing and configuring Emacs packages. Of course, it does not actually install the packages, but instead defers to a package manager, like straight.el (which comes with use-package integration by default).

To use use-package, first install it with straight.el:

(straight-use-package 'use-package)

Now use-package will use straight.el to automatically install missing packages if you provide :straight t:

(use-package el-patch
  :straight t)

You can still provide a custom recipe for the package:

(use-package el-patch
  :straight (el-patch :type git :host github :repo "raxod502/el-patch"
                      :fork (:host github
                             :repo "your-name/el-patch")))

Specifying :straight t is unnecessary if you set straight-use-package-by-default to a non-nil value. (Note that the variable use-package-always-ensure is associated with package.el, and you should not use it with straight.el.)

To learn more, see the documentation on straight.el's use-package integration.

Edit packages locally

One of the biggest strengths of straight.el is that editing packages locally is trivial. You literally just edit the files (find-function and friends all work as you would expect). Packages will be automatically rebuilt if necessary when Emacs next starts up.

You can even commit your changes and push or pull to various remotes using Git. You have complete control over your packages' Git repositories.

To learn more, see the documentation on the package lifecycle.

Automatic repository management

While being able to make arbitrary changes to your packages is very powerful, it can also get tiring to keep track of the all those changes. For this reason, straight.el provides a suite of powerful interactive workflows to perform bulk operations on your packages.

To restore each package to its canonical state (a clean working directory with the main branch checked out, and the remotes set correctly), run M-x straight-normalize-package or M-x straight-normalize-all.
To fetch from each package's configured remote, run M-x straight-fetch-package-and-deps or M-x straight-fetch-all; to also fetch from the upstream for forked packages, supply a prefix argument.
To merge changes from each package's configured remote, run M-x straight-merge-package-and-deps or M-x straight-merge-all; to also merge from the upstream for forked packages, supply a prefix argument.
To push all local changes to each package's configured remote, run M-x straight-push-package or M-x straight-push-all.

All of these commands are highly interactive and ask you before making any changes. At any point, you can stop and perform manual operations with Magit or other tools in a recursive edit.

To learn more, see the documentation on bulk repository management.

Configuration reproducibility

To save the currently checked out revisions of all of your packages, run M-x straight-freeze-versions. The resulting file (~/.emacs.d/straight/versions/default.el), together with your init-file, perfectly define your package configuration. Keep your version lockfile checked into version control; when you install your Emacs configuration on another machine, the versions of packages specified in your lockfile will automatically be checked out after the packages are installed. You can manually revert all packages to the revisions specified in the lockfile by running M-x straight-thaw-versions.

To learn more, see the documentation on version lockfiles.

Conceptual overview

This section describes, at a high level, how the different mechanisms in straight.el play together. This illustrates how straight.el manages to accomplish all of its guiding principles.

TL;DR

straight.el operates by cloning Git repositories and then symlinking files into Emacs' load path. The collection of symlinked files constitutes the package, which is defined by its recipe. The recipe also describes which local repository to link the files from, and how to clone that repository, if it is absent.

When you call straight-use-package, the recipe you provide is registered with straight.el for future reference. Then the package's repository is cloned if it is absent, the package is rebuilt if its files have changed since the last build (as determined by find(1)), and its autoloads are evaluated.

You can also provide only a package name, in which case the recipe will be looked up in one of several configurable recipe repositories, which are just packages themselves (albeit with the build step disabled).

straight.el determines which packages are installed solely by how and when straight-use-package is invoked in your init-file.

What is a package?

A package is a collection of Emacs Lisp (and possibly other) files. The most common case is just a single .el file, but some packages have many .el files, and some even have a directory structure.

Note that a package is defined only as a collection of files. It doesn't necessarily correspond to a Git repository, or an entry on MELPA, or anything like that. Frequently there is a relationship between all of these concepts, but that relationship does not always have to be direct or one-to-one.

A package also has a name, which must be unique. This is the name that is used for the folder holding the package's files. It is frequently the same as the name of a Git repository, or an entry on MELPA, but again this does not have to be the case.

Where do packages come from?

If you really wanted all of your packages to be unambiguously defined, you could just copy and paste all of their files into version control. But that would defeat the purpose of using a package manager like straight.el. In straight.el, packages are defined by two sources of information:

a local repository
a build recipe

The local repository is just a directory containing some files. Of course, it also has a name, which may or may not be the same as the package's name. Frequently, the local repository is also a Git repository, but this is not necessary.

The build recipe is not a literal data structure. It is a concept that represents a certain subset of the package's recipe. Specifically, the :files, :local-repo, and :no-build keywords.

To transform this information into an actual package that Emacs can load, straight.el builds the package. This means that some symbolic links are created in the package's directory that point back into the local repository's directory. Exactly how these symlinks are created is determined by the :files directive, and which local repository the symlinks point to is determined by the :local-repo directive.

After the symlinks are created, the resulting files are byte-compiled, and their autoloads are generated and written into a file in the package's directory.

If :no-build is specified, however, this entire process is skipped. This mechanism is used for recipe repositories.

What does this look like on disk?

The local repositories are kept in ~/.emacs.d/straight/repos, and the built packages are kept in ~/.emacs.d/straight/build. If you have initialized straight.el and loaded package el-patch, then your ~/.emacs.d/straight directory will look roughly like this (some irrelevant details have been omitted for pedagogical purposes):

straight
├── build
│   ├── el-patch
│   │   ├── el-patch-autoloads.el
│   │   ├── el-patch.el -> ~/.emacs.d/straight/repos/el-patch/el-patch.el
│   │   └── el-patch.elc
│   └── straight
│       ├── straight-autoloads.el
│       ├── straight.el -> ~/.emacs.d/straight/repos/straight.el/straight.el
│       └── straight.elc
└── repos
    ├── el-patch
    │   ├── CHANGELOG.md
    │   ├── LICENSE.md
    │   ├── README.md
    │   └── el-patch.el
    └── straight.el
        ├── LICENSE.md
        ├── Makefile
        ├── README.md
        ├── bootstrap.el
        ├── install.el
        └── straight.el

As you can see, the package names are el-patch and straight. While el-patch is built from a local repository of the same name, straight is built from a local repository by the name straight.el. Also note that only .el files are symlinked, since only they are relevant to Emacs.

Where do repositories come from?

Local repositories provide a way to define packages without specifying the contents of all of their files explicitly. But that's not helpful without a higher-level way to define local repositories without specifying the contents of all of their files. In straight.el, local repositories are defined by two sources of information:

a fetch recipe
the version lockfiles

The fetch recipe is, like the build recipe, a concept representing a certain subset of the package's overall recipe. The situation is more interesting here because straight.el supports multiple version-control backends. The version-control backend specified by the fetch recipe is determined by the :type directive (which defaults to straight-default-vc). Each version-control backend then accepts some set of additional directives. For example, the git backend accepts:

:repo
:host
:branch
:nonrecursive
:fork

If a local repository is not present, then its fetch recipe describes how to obtain it. This is done using the straight-vc-clone function, which delegates to one of the backend implementations of the clone operation, according to :type. (The option :type built-in is a special case that results in all version-control operations for the package being ignored.)

However, even with a particular repository source specified, there is still the question of which version of the repository to use. This is where the version lockfiles come in. When a local repository is cloned, the version lockfiles are searched to see if there is a particular commit specified for that local repository's name. If so, that commit is checked out. (For the git backend, commits are 40-character strings representing SHA-1 hashes, but the representation of a commit identifier could be different across different backends.)

The straight-freeze-versions and straight-thaw-versions methods also use backend-delegating methods; in this case, they are straight-vc-get-commit and straight-vc-check-out-commit.

The fetch recipe and version lockfiles, together with the configuration options for straight.el, precisely define the state of a local repository. Of course, you may make any changes you want to the local repository. But this information defines a "canonical" state that you may revert to at any time.

When this information is combined with the build recipe, straight.el is able to construct canonical, universal versions of your Emacs packages that will be the same everywhere and forever.

Note that you do not have to provide fetch recipes or version lockfiles. You may manage your local repositories manually, if you wish, although this has obvious disadvantages in terms of repeatability and maintainability.

What does it mean to load a package?

A prerequisite to loading a package is making sure the package has been built. After that is done, loading the package means adding its directory to the load path and evaluating its autoloads file.

Adding the directory to the load path means that you can use require to load the package's files. Note that straight.el does not do this for you, since loading packages immediately is usually not necessary and it immensely slows down Emacs startup.

Evaluating the autoloads file means that calling the functions that are defined in the autoloads file will automatically require the files that define those functions. All modern packages define their functions in autoloads and are designed to be loaded on-demand when those functions are called. Antiquated packages may need you to explicitly define autoloads, or to just require the package right away.

Where do recipes come from?

straight-use-package does not require an actual recipe. You can just give it a package name, and it will look up the recipe. This is done using recipe repositories. Recipe repositories are set up as a swappable backend system, much like the version-control backend system.

A recipe repository consists of four parts:

a fetch recipe for the local repository (this will typically include the :no-build directive, since recipe repositories usually do not need to be built)
a function that, provided the local repository is already available, returns a list of all packages that have recipes in the recipe repository
a function that, given a package name, returns the recipe for that package, or nil if the recipe repository does not provide a recipe for the package
an entry in straight-recipe-repositories indicating that the recipe provided actually corresponds to a recipe repository (otherwise it would just be a regular package)

Note that recipe repositories are implemented as regular packages! This means that all the usual package management operations work on them as well. It also means that you use straight-use-package to register them (although typically you will provide arguments to straight-use-package so that the recipe repository is only registered, and not cloned until it is needed; see the section on straight-use-package).

If you give straight-use-package just a package name, then each recipe repository in straight-recipe-repositories is checked for a recipe for that package. Once one is found, it is used. Otherwise, an error is signaled (unless the package is built-in to Emacs, according to package.el).

Note that straight.el uses its own recipe format which is similar, but not identical, to the one used by MELPA. The recipe repository backends abstract over the formatting differences in different recipe sources to translate recipes into the uniform format used by straight.el. When you run M-x straight-get-recipe, the translated recipe is what is returned.

What happens when I call `straight-use-package`?

There are three actions that straight-use-package can take:

Register a package's recipe with straight.el.
Clone a package's local repository, if it is missing.
Build a package, if it has been changed since the last time it was built, and load it.

These actions must be performed in order. Depending on the arguments you pass to straight-use-package, one, two, or all three may be performed.

The normal case is to do all three. The fetch recipe is only required if the local repository is actually missing, but the build recipe is always required.

Deferred installation can be accomplished by telling straight-use-package to stop if the local repository is not already available. The deferred installation can be triggered by invoking straight-use-package again, but telling it to go ahead and clone the repository (this is the default behavior). Because straight-use-package already registered the package's recipe the first time, you don't have to provide it again.

In some extraordinary circumstances (such as when straight.el is bootstrapping its own installation), it may be desirable to clone a package's local repository if it is missing, but to stop before building and loading the package. This can also be done by straight-use-package.

What does it mean to register a package?

Package registration is the first action taken by straight-use-package, before building and cloning. First, if only a package name was provided to straight-use-package, a recipe is obtained from the configured recipe repositories. Next, the resulting recipe is recorded in various caches.

This is important, since it allows for several things to happen:

if you later want to perform another operation on the package using straight.el, you do not need to provide the recipe again
if you use a custom recipe for Package A, and Package B requires Package A as a dependency, your custom recipe is remembered and re-used when Package A is used as a dependency, to avoid conflicts.
when multiple packages are built from the same local repository, and you have specified a custom fetch recipe for one of those packages, straight.el can intelligently merge that fetch recipe into the automatically retrieved recipes of dependencies, in order to avoid conflicts.
straight.el knows which packages you have installed, if you want to perform interactive operations on them.
if you accidentally provide two different recipes for the same package, straight.el can issue a helpful warning, since this may lead to surprising behavior.

How does `straight.el` know when to rebuild packages?

When you request for straight.el to load a package (using straight-use-package), it first checks if the package needs to be rebuilt. This means that some of the files in its local repository have been modified since the last time the package was built. straight.el uses an optimized find(1) command to check for package modifications, and it uses some caching mechanisms to perform bulk find(1) operations on multiple packages, to speed up these checks (although it never performs optimizations that may result in erroneous behavior).

This check occurs during Emacs init, when your init-file makes calls to straight-use-package. You may notice a significant delay on the first straight-use-package call, because this is when straight.el performs a bulk find(1) call and caches the results for later usage (this speeds up init considerably). The total delay is likely to be on the order of 100ms for a double-digit number of packages.

The rebuild detection system is what allows for you to make changes to packages whenever you would like, without performing any additional operations.

(Packages are also rebuilt when their recipes change, of course.)

How does `straight.el` know what packages are installed?

straight.el does not require you to declare a central list of packages anywhere, like Cask does. Instead, it determines what packages are to be loaded implicitly, by your invocations of straight-use-package during Emacs initialization. Furthermore, straight.el allows you to install packages after initialization using M-x straight-install-package (or even by evaluating straight-use-package forms). However, straight.el still provides advanced features such as bulk package management and version locking. This creates some interesting challenges which other package managers do not have to deal with.

straight.el solves these problems using a concept called transactions. The operation of the transaction system is mostly transparent to the user, at least in recent versions of straight.el. Basically, it provides a way for straight.el to keep track of what happens within a single user operation (e.g. evaluate a buffer of straight-use-package calls, or load the init-file).

straight.el uses the transaction system to keep track of what packages you request in your init-file. If you invoke straight-use-package interactively, then this invalidates that information, since you have now requested a package that is not in your init-file. For this reason, if you have invoked straight-use-package interactively, running M-x straight-freeze-versions will prompt you to first reload your init-file.

Comparison to other package managers

(Disclaimer: while I try to be as objective and comprehensive as possible here, I'm obviously biased. Please submit corrections if I have unfairly disparaged your favorite package manager!)

There are many package managers for Emacs, ranging from simple scripts to download files from EmacsWiki to full-featured package management solutions like straight.el. Here are the most feature-rich alternatives to straight.el:

package.el: de facto standard, bundled with Emacs.
Quelpa: allows you to use external sources like GitHub with package.el. Essentially a local MELPA.
Cask: another package.el wrapper. Specify your dependencies in a Cask file; can be used for project management or an Emacs configuration.
el-get: ridiculously OP in terms of how many different sources you can pull packages from (package.el, every known VCS, distro package managers, go get(!!)).
Borg: assimilates packages as Git submodules into .emacs.d, relying on Emacsmirror.
"Screw package managers! I'll just handle it all myself!"

TL;DR

Here is a summary of the main differences in philosophy between the package managers:

Use package.el if you want package management to be as easy as possible, and do not much care for installing packages from specific sources, keeping track of their versions, or doing local development on them.
Use Quelpa if you like package.el but really wish you could specify the sources of your packages.
Use Cask if you like package.el but wish it came with some project management tools, as well.
Use el-get if you want to easily install packages from as many different sources as possible.
Use Borg if you like a more lightweight approach to package management that leverages existing solutions, if contributing changes to packages upstream is important to you, and if using Git submodules isn't a deal-breaker.
Use the manual approach if you need to contribute changes to a package that is versioned in something other than Git.
Use straight.el if you like reproducibility in your Emacs configuration, you regularly contribute changes to packages upstream, you think deferred installation is a really great idea, or you are writing an Emacs configuration to be used by others.

And here is a brief list of the main reasons you might not want to use straight.el:

straight.el is largely unusable if you do not have Git installed, although it is still possible to use the package-building features if you manage your repositories manually (you also cannot use the magic bootstrap snippet, in that case). If you don't want to install Git, you'll have to use package.el or take the manual approach.
straight.el is not built in to Emacs. If you want something that will work right out of the box, you're stuck with package.el or the manual approach.
straight.el takes a minute or two to update all your packages, since it does not rely on a centralized server. If you want quick update checking, you'll have to use package.el.
straight.el does not provide any user interface for package management. For that, you'll have to use package.el, el-get, Cask, or Borg (which expects you to use epkg for browsing packages).
straight.el does not currently support using only stable versions of packages (i.e. tagged revisions), although this is a planned feature. If this is important to you, you probably want to go with package.el (with GNU ELPA and MELPA Stable), Cask, or Quelpa.
straight.el does not currently support arbitrary build commands like make, although this is a planned feature. This feature is supported by el-get and Borg.
If you don't like having to modify your init-file to do package management, then straight.el is absolutely not for you. You want package.el, Quelpa, el-get, or Borg.
If you really want to contribute changes to packages that are not versioned in Git, then straight.el will not help you. You'll have to manage the package's repository manually. Unfortunately, there is no existing package manager that supports both non-Git version-control systems and contributing changes upstream. You'll have to go with the manual approach.
straight.el does not provide project management tools. It is a package manager. If you want project management tools, check out Cask.
straight.el is quite new and moving fast. Things might break. The other package managers can generally be ranked as follows, from most active to least active: el-get, Quelpa, Borg, Cask, package.el (glacial).

Comparison to `package.el`

package.el downloads pre-built packages from central servers using a special (undocumented?) HTTP protocol, while straight.el clones Git (or other) repositories and builds packages locally.

Advantages of `straight.el`

straight.el allows you to install a package from any branch of any Git repository. package.el only allows you to install a package from a package.el-compliant central server.
straight.el allows you to check out any Git revision of any package. package.el only allows you to install the latest version, and there is no way to downgrade.
straight.el supports Emacsmirror, while package.el does not.
straight.el uses your init-file as the sole source of truth for package operations. package.el loads every package you ever installed at startup, even if some of those packages are no longer referenced by your init-file.
straight.el supports 100% reproducibility for your Emacs packages with version lockfiles. package.el cannot provide reproducibility for the set of packages installed, the central servers they were installed from, or the versions in use.
straight.el allows you to make arbitrary changes to your packages locally. While it is possible to make local changes to package.el packages, these changes cannot be version-controlled and they will be silently overwritten whenever package.el performs an update.
straight.el allows you to perform arbitrary version-control operations on your package's Git repositories, including contributing changes upstream. straight.el has explicit support for specifying both an upstream and a fork for a package. Contributing changes upstream with package.el is impossible.
straight.el is designed with emacs -Q bug reports in mind. package.el is unsuitable for minimal bug reproductions, since it automatically loads all of your packages on any package operation, even in emacs -Q.
straight.el operates quietly when all is going well. package.el displays all messages, errors, and warnings that come from byte-compilation and autoload generation.
straight.el considers modifying the user's init-file extremely uncouth. package.el aggressively inserts a call to package-initialize into the init-file if it is not already present, whenever any package management operation is performed.
straight.el has a profile system that allows users of someone else's Emacs configuration to manage an additional subset of packages, or to override upstream package configuration, without forking the upstream. package.el has no such concept.
straight.el is developed openly on GitHub, using a modern issue tracker and continuous integration from Travis CI. It welcomes contributions of any type. straight.el is licensed under the permissive MIT license and does not require a copyright assignment. straight.el is developed actively and has explicit support for installing development versions of itself, as well as for contributing upstream changes. package.el is maintained as a part of Emacs core, meaning that the contribution process is poorly documented and discouraging. Releases of package.el coincide with releases of Emacs, which are infrequent and inflexible. There is no issue tracker specifically for package.el, only the Emacs bug tracker and the emacs-devel mailing list. Contributing to package.el requires a poorly-documented, cumbersome copyright assignment process and is done by submitting patches to an antiquated mailing list, unsupported by modern code review tooling or continuous integration.

Advantages of `package.el`

package.el does not require that you have Git installed, since the central server deals with where the packages originally came from. straight.el cannot be used at all without Git.
package.el is built in to Emacs and does not require additional configuration to get started with. straight.el requires the use of a 10-line bootstrap snippet in your init-file.
package.el can perform bulk package updates more quickly since it relies on central servers.
package.el has a user interface for package management that also displays package metadata. straight.el has no user interface for package management; any UI is provided by the user's completing-read framework.
package.el does not require you to touch your init-file to install packages, while straight.el absolutely refuses to permanently install a package without an explicit reference to it in your init-file (although this may be considered an advantage, depending on your perspective).
Using MELPA Stable, package.el can install only stable versions of packages. By default, package.el also installs only stable versions of packages from GNU ELPA. These modes of operation are unsupported by straight.el at this time, although this is a planned feature.

Additional notes

package.el and straight.el usually take approximately the same time to install packages, despite the fact that straight.el is cloning entire Git repositories. This is because network latency and byte-compilation are the dominant factors.
Some package.el servers build packages from non-Git upstreams. package.el can install these packages, while straight.el cannot. However, since package.el has no version-control support, this is more or less equivalent to installing those packages from the Emacsmirror, which straight.el can do by default.

Comparison to Quelpa

Quelpa allows for fetching packages from arbitrary sources and building them into a format that can be installed by package.el. straight.el has a philosophy which is fundamentally incompatible with package.el, and non-compatibility with package.el is one of its design goals.

Advantages of `straight.el`

straight.el has out-of-the-box compatibility with MELPA, GNU ELPA, and Emacsmirror, while Quelpa only has support for MELPA. To use GNU ELPA, you must drop down to package.el. Emacsmirror is not supported by default, although it is easy to specify an Emacsmirror repository in a recipe. While Quelpa allows you to specify custom recipe folders, it does not have support for cloning these folders automatically from version control, nor for generating the recipes in any way other than copying them literally from files. straight.el allows you full flexibility in this regard.
straight.el has integrated support for selecting particular Git revisions of packages. This process is more manual in Quelpa, as it requires placing the commit hash into the recipe, which disables updates.
straight.el uses your init-file as the sole source of truth for package operations. Since Quelpa is based on package.el, it also loads every package you ever installed at startup, even if those packages are no longer referenced by your init-file. Furthermore, there is an additional caching layer, so that deleting a package from the package.el interface and removing it from your init-file still does not actually delete it.
straight.el supports 100% reproducibility for your Emacs packages with version lockfiles. Quelpa can theoretically provide some measure of reproducibility, but this requires significant manual effort since all packages are not associated with specific revisions by default, nor is the revision of MELPA saved anywhere.
straight.el allows you to make arbitrary changes to your packages locally. While it is possible to make local changes to Quelpa packages, there are two places to do so: the built package, which is the default destination of find-function, and the original repository. Changes to the former are not version-controlled and will be silently overwritten by package.el operations, while changes to the latter will be silently overwritten by Quelpa operations.
straight.el has explicit support for configuring both an upstream repository and a fork for the same package. Quelpa does not have such a concept.
straight.el allows you complete control over how your repositories are managed, and the default behavior is to draw all packages versioned in a single repository from a single copy of that repository. Quelpa is hardcoded to require a separate repository for each package, so that installing Magit requires three copies of the Magit repository.
straight.el builds packages using symlinks, meaning that find-function works as expected. Quelpa builds packages by copying, a feature inherited from MELPA. This means that find-function brings you to the built package, instead of the actual repository, which is not version-controlled and will be overwritten whenever package.el performs an update.
straight.el allows you to perform arbitrary version-control operations on your package's Git repositories. Quelpa allows this, but all local changes will be silently overridden whenever Quelpa performs an update.
straight.el is designed with emacs -Q bug reports in mind. Since Quelpa is based on package.el, it is also unsuitable for minimal bug reproductions, since it automatically loads all of your packages on any package operation, even in emacs -Q.
straight.el operates quietly when all is going well. Since Quelpa is based on package.el, it displays all messages, errors, and warnings that come from byte-compilation and autoload generation. It also displays additional messages while cloning Git repositories, downloading files, and building packages from their repositories into package.el format.
straight.el does not modify your init-file. Since Quelpa is based on package.el, it inherits the behavior of aggressively inserting a call to package-initialize into your init-file on any package management operation.
straight.el has a profile system that allows users of someone else's Emacs configuration to manage an additional subset of packages, or to override upstream package configuration, without forking the upstream. Quelpa has no such concept.

Advantages of Quelpa

Quelpa supports all the version-control systems supported by MELPA, which is to say almost every commonly and uncommonly used VCS. straight.el only supports Git, although it is designed to support other version-control backends.
Quelpa allows for installing only stable versions of packages, from any source. This mode of operation is unsupported by straight.el, although it is a planned feature.
Since Quelpa is based on package.el, it inherits a user interface for package management that also displays package metadata. straight.el has no such interface.

Additional notes

straight.el and Quelpa both allow you to manage your package's local repositories manually, if you wish.
In principle, straight.el and Quelpa have identical package installation times, since they are performing the same operations. In practice, Quelpa is slightly slower since it builds packages by copying rather than symlinking, and it clones multiple copies of the same Git repository when multiple packages are built from it.
straight.el encourages you to keep a tight handle on your package versions by default. Quelpa encourages you to stick to the latest versions of your packages, and to upgrade them automatically.

Comparison to Cask

I have not used Cask extensively, so please feel especially free to offer corrections for this section.

Cask installs packages using the package.el protocol, based on a Cask file written in the Cask DSL. straight.el eschews package.el entirely, and clones packages from source based on how you invoke straight-use-package in your init-file.
Cask focuses more on being a build manager, like Maven or Leiningen, while straight.el focuses exclusively on being a package manager.

Advantages of `straight.el`

straight.el has out-of-the-box compatibility with Emacsmirror, while Cask only supports package.el-compliant repositories. However, it is easy to specify an Emacsmirror repository in a recipe. Cask does not support custom package sources. straight.el supports MELPA, GNU ELPA, and Emacsmirror, and allows you to add any other sources you would like.
straight.el has integrated support for selecting particular Git revisions of packages. This process is more manual in Cask, as it requires placing the commit hash into the recipe, which disables updates.
straight.el uses your init-file as the sole source of truth for package operations. Since Cask is based on package.el, it loads every package you ever installed at startup, even if some of those packages are no longer referenced by your Cask file.
straight.el determines your package management configuration implicitly by detecting how you call straight-use-package in your init-file and making the appropriate changes immediately. Cask requires manual intervention (for example, issuing a cask install command when you have updated your Cask file). However, both straight.el and Cask can be considered declarative package managers.
straight.el supports 100% reproducibility for your Emacs packages with version lockfiles. Cask can theoretically provide some measure of reproducibility, but this requires significant manual effort since all packages are not associated with specific revisions by default, nor is the revision of Cask saved anywhere.
straight.el allows you to make arbitrary changes to your packages locally. While it is possible to make local changes to Cask packages, these will not be version-controlled and they will be silently overwritten or shadowed when Cask performs an update.
straight.el allows you to perform arbitrary version-control operations on your package's Git repositories, including contributing changes upstream. straight.el has explicit support for specifying both an upstream and a fork for a package. Contributing changes upstream with Cask is impossible.
straight.el is designed with emacs -Q bug reports in mind. Cask appears to be unsuitable for minimal bug reproductions, since there does not appear to be a straightforward way to load a single package, without loading all other packages configured in your Cask file.
straight.el operates quietly when all is going well. Since Cask is based on package.el, it displays all messages, errors, and warnings that come from byte-compilation and autoload generation.
straight.el has a profile system that allows users of someone else's Emacs configuration to manage an additional subset of packages, or to override upstream package configuration, without forking the upstream. Cask has no such concept.

Advantages of Cask

Cask provides a useful toolbox of operations for project management, which are completely absent from straight.el.
Since Cask is based on package.el, it does not require that you have Git installed. (It does require Python, however.) straight.el is mostly unusable without Git.
Since Cask is based on package.el, it can perform bulk package updates more quickly than straight.el.
Since Cask is based on package.el, it inherits a user interface for package management that also displays package metadata.
Since Cask is based on package.el, you can install packages without editing a file manually, although this rather defeats the entire purpose of using Cask instead of package.el. straight.el absolutely refuses to permanently install a package without an explicit reference to it in your init-file (although this may be considered an advantage, depending on your perspective).
Using MELPA Stable, Cask can install only stable versions of packages. By default, Cask also installs only stable versions of packages from GNU ELPA. These modes of operation are unsupported by straight.el at this time, although this is a planned feature.
Cask supports more version-control systems than straight.el (which only supports Git).

Comparison to el-get

I have not used el-get extensively, so please feel especially free to offer corrections for this section.

Both el-get and straight.el implement their own package management abstractions instead of delegating to package.el. However:
- el-get goes the route of adding as many package sources as possible (e.g. package.el, many different version-control systems, various specific websites, and even system package managers) so that packages can be used very easily.
- straight.el only supports Git and in doing so is able to provide more advanced package management features.

Advantages of `straight.el`

straight.el uses your init-file as the sole source of truth for package operations. el-get has additional metadata stored outside the init-file, although specifying all packages in your init-file is a supported mode of operation.
straight.el supports 100% reproducibility for your Emacs packages with version lockfiles. el-get can theoretically provide some measure of reproducibility, but this requires significant manual effort since all packages are not associated with specific revisions by default, nor is the revision of el-get saved anywhere.
straight.el allows you to make arbitrary changes to your packages locally, and conflicts during updates are presented to the user and resolved interactively. While it is possible to make local changes to el-get packages, the el-get manual warns that such changes may break the update mechanism.
straight.el has explicit support for configuring both an upstream repository and a fork for the same package. el-get does not have such a concept.
straight.el allows you to perform arbitrary version-control operartions on your package's Git repositories. el-get allows this, but local changes will be overwritten when el-get performs an update.
straight.el provides a suite of powerful interactive workflows for performing bulk operations on your package's Git repositories. el-get only allows you to install, uninstall, and update packages.
straight.el operates quietly when all is going well. el-get reports its progress verbosely.
straight.el has a profile system that allows users of someone else's Emacs configuration to manage an additional subset of packages, or to override upstream package configuration, without forking the upstream. el-get has no such concept.

Advantages of el-get

el-get supports virtually all known version-control systems, as well as system package managers, EmacsWiki, arbitrary HTTP, and even go get. straight.el supports only Git, although it does allow you to manage your local repositories manually if you would like.
el-get has been around since 2010 and is on its fifth major version, whereas straight.el was created in January 2017 and is only now approaching a 1.0 release. Clearly, el-get is more stable, although despite its recency straight.el is already almost 50% of the size of el-get, by the line count. Both package managers are actively maintained.
el-get has a recipe format which is several orders of magnitude more powerful than that of straight.el, since it supports many more package sources that can be configured and since it allows for a more complex build process.
el-get provides a number of features for running per-package initialization and setup code, including pulling that code from arbitrary sources. straight.el does not support this and expects you to use a dedicated tool like use-package (with which integration is built in) for that purpose.
el-get has a user interface for package management that also displays package metadata, similarly to package.el. straight.el has no user interface for package management; any UI is provided by the user's completing-read framework.

Comparison to Borg

Borg and straight.el are perhaps the two most similar package managers on this list. The difference is that Borg is very minimal and expects you to complement it with other tools such as Magit, epkg, use-package, and auto-compile. On the other hand, straight.el aspires to be a one-stop package management solution, although it does not try to replace dedicated version-control packages (Magit) or dedicated package configuration packages (use-package).
Borg uses Git submodules, while straight.el uses independently managed Git repositories.

Advantages of `straight.el`

straight.el supports MELPA, GNU ELPA, Emacsmirror, and custom recipe sources. Borg only supports Emacsmirror and custom recipe sources. However, as the Emacsmirror is a near-complete superset of both GNU ELPA and MELPA, this does not necessarily mean you have access to more packages: it just means you benefit from the recipe maintenance efforts of the MELPA team and the Emacsmirror team, rather than only the latter.
Borg, even when combined with related tools, do not allow for the kind of massive interactive repository management provided by straight.el.
straight.el supports deferred and conditional installation. This is not supported by Borg, although it could in principle be implemented via lazy cloning of submodules.
straight.el provides an API designed for other version-control backends to be added in future. Borg is inextricably tied to Git.
The interface for Git submodules has a number of sharp edges.
straight.el provides dependency management. This is a manual process in Borg.
straight.el provides mechanisms for updating your packages. This is a manual process in Borg.
straight.el is configured solely by how you use in your init-file. Configuring Borg requires customizing ~/.emacs.d/.gitmodules, which means (for example) that you cannot generate recipes dynamically. (However, the handling of configuration is planned to be improved in a future release.)
straight.el has a profile system that allows users of someone else's Emacs configuration to manage an additional subset of packages, or to override upstream package configuration, without forking the upstream. Borg has no such concept.

Advantages of Borg

Borg does a heck of a lot less magic, so if you want a solution with simple implementation details, straight.el may not be for you. (But see the developer manual and docstrings, first.)
Borg supports arbitrary build commands; straight.el does not (although this is a planned feature).

Comparison to the manual approach

The manual approach is to download packages yourself and put them on your load-path. straight.el is more or less what you get when you take the manual approach, think very hard about the best way to do everything, and then automate all of it.

Advantages of `straight.el`

straight.el figures out where to clone your packages from for you.
straight.el byte-compiles your packages for you and generates their autoloads automatically.
straight.el frees you from needing to manually recompile and regenerate autoloads.
straight.el keeps track of dependencies for you.
straight.el provides tools to manage all your packages in bulk, which would otherwise be a long, tedious process.
straight.el allows you to get reproducibility for your configuration without needing to keep all of your packages under version control.
straight.el (when used with use-package) automates the complex process of deferred installation.
straight.el links packages into a separate build directories. Running packages directly from their repositories has a number of problems, including:
- making it impossible to run only one package, if others are provided in the same repository.
- making your working directory dirty when the package author forgot to add their build artifacts like *.elc and autoload files to the .gitignore.
- instantly losing compatibility with MELPA recipes.
straight.el offers you a single entry point to install only a single package in isolation, for a minimal bug reproduction. With the manual approach this would be more complicated, especially if the package has dependencies.
straight.el frees you from needing to think about package management, since I already did all the thinking to figure how best to design everything.

Advantages of the manual approach

No dependencies.
You learn a lot, if you don't give up first.
You might end up writing a package manager (case in point).
This is the only way to deal with packages that have non-Git upstreams which you need to contribute changes to. (However, you can always use the manual approach for one package and straight.el for the rest. Or you can just eschew straight.el's version-control support for that package, and use it only for building the package.)

User manual

This section tells you everything you need to know about the user-facing features of straight.el. For implementation details, see the developer manual. It may also be helpful to get some perspective on the overarching concepts of straight.el from the conceptual overview.

Bootstrapping `straight.el`

In order to use straight.el, you will need to somehow get it loaded into Emacs. (This is easy for package.el, since package.el is built in to Emacs. straight.el must work a little harder.)

straight.el comes with a file to do just this, bootstrap.el. All you need to do is load that file. You can do this with M-x load-file or by a call to load in your init-file. However, there is an obvious shortcoming: bootstrap.el will only be available once straight.el is already installed.

You could just invoke git clone from your init-file, if straight.el is not installed, but then you would have to manually take care of selecting the correct branch, parsing your version lockfile to check out the right revision, and so on. Instead, you can just use this snippet, which uses a copious amount of magic to take care of all these details for you:

(defvar bootstrap-version)
(let ((bootstrap-file
       (expand-file-name "straight/repos/straight.el/bootstrap.el" user-emacs-directory))
      (bootstrap-version 5))
  (unless (file-exists-p bootstrap-file)
    (with-current-buffer
        (url-retrieve-synchronously
         "https://raw.githubusercontent.com/raxod502/straight.el/develop/install.el"
         'silent 'inhibit-cookies)
      (goto-char (point-max))
      (eval-print-last-sexp)))
  (load bootstrap-file nil 'nomessage))

Despite the reference to develop, this snippet actually installs from the master branch by default, just like every other package. Furthermore, the correct revision of straight.el is checked out, if you have one specified in your lockfile. Even better, you can override the recipe for straight.el, just like for any other package.

Installing packages programmatically

The primary entry point to straight.el is the straight-use-package function. It can be invoked interactively (for installing a package temporarily) or programmatically (for installing a package permanently). This section covers the programmatic usage; see later for interactive usage.

Here is the basic usage of straight-use-package:

(straight-use-package 'el-patch)

This will ensure that the package el-patch is installed and loaded. (Note that straight-use-package takes a symbol, not a string, for the name of the package.) Precisely, this is what happens:

If the local Git repository for el-patch is not available, it is cloned, and the appropriate revision is checked out (if one is specified in your version lockfiles).
If the local Git repository has been modified since the last time the package was built, it is rebuilt. This means:
- The .el files are symlinked into a separate directory to isolate them from other, irrelevant files.
- The main package file is checked for dependencies, which are installed recursively if necessary using straight-use-package.
- The .el files are byte-compiled.
- Autoloads are extracted from the .el files and saved into a separate file.
The package's directory is added to Emacs' load-path.
The package's autoloads are evaluated.

Package authors should note that straight.el checks for dependencies that are specified in the package.el format. To spare you reading that documentation, this is either a Package-Requires header in PACKAGENAME.el, or an argument to a define-package invocation in PACKAGENAME-pkg.el. Despite the many shortcomings of package.el, it has done a good job of creating a standardized format for dependency declarations.

There is one exception to the above statement: not all entries specified in the Package-Requires header necessarily correspond to packages. For example, specifying a minimum Emacs version for a package is done by depending on the emacs pseudo-package. Such packages are simply ignored by straight.el, using the variable straight-built-in-pseudo-packages.

Note that loading a package does not entail invoking require on any of its features. If you wish to actually load the files of the package, you need to do this separately. This is because most packages do not need to be loaded immediately, and are better served by the autoload system.

Installing with a custom recipe

straight-use-package can also take a list instead of a symbol. In that case, the first member of the list is a symbol giving the package name, and the remainder of the list is a property list providing information about how to install and build the package. Here is an example:

(straight-use-package
 '(el-patch :type git :host github :repo "raxod502/el-patch"
            :fork (:host github
                   :repo "your-name/el-patch")))

If you give straight-use-package just a package name, then a recipe will be looked up by default (see the section on recipe lookup). You can see the default recipe for a package by invoking M-x straight-get-recipe.

To learn more, see the section on the recipe format.

Additional arguments to `straight-use-package`

The full user-facing signature of straight-use-package is:

(straight-use-package PACKAGE-OR-RECIPE &optional NO-CLONE NO-BUILD)

As discussed previously, by default straight-use-package will do three things:

Register the recipe provided with straight.el.
Clone the package's local repository, if it is absent.
Rebuild the package if necessary, and load it.

By providing the optional arguments, you may cause processing to halt before all three of these tasks are completed. Specifically, providing NO-CLONE causes processing to halt after registration but before cloning, and providing NO-BUILD causes processing to halt after cloning (if necessary) but before building and loading.

straight.el supports lazy-loading by means of a special value for NO-CLONE, the symbol lazy. If this symbol is passed, then processing will halt at the clone step, unless the package is already cloned. This means that the package is built and loaded if it is already installed, but otherwise installation is deferred until later. When you want to trigger the lazy installation, simply call straight-use-package again, but without NO-CLONE. (There is no need to pass the recipe again; see recipe lookup.)

You can also pass functions for NO-CLONE or NO-BUILD, which will be called with the package name as a string; their return values will then be used instead.

Note that if it makes no sense to build a package, then you should put :no-build t in its recipe, rather than specifying NO-BUILD every time you register it with straight.el. (This is especially relevant when writing recipes for recipe repositories.)

Variants of `straight-use-package`

For convenience, straight.el provides some functions that wrap straight-use-package with particular arguments, to cover all of the common cases. Each of these functions takes only a package name or recipe, and no additional arguments.

straight-register-package: always stop after the registration step. This may be useful for specifying the recipe for an optional dependency (see recipe lookup, but see also recipe overrides).
straight-use-package-no-build: always stop before the build step. This is used by straight-freeze-versions to make sure packages are cloned, since building them is unnecessary for writing the lockfiles.
straight-use-package-lazy: stop at the clone step if the package's local repository is not already cloned. This is used for lazy-loading.

Customizing when packages are built

By default, when straight.el is bootstrapped during Emacs init, it uses a bulk find(1) command to identify files that were changed since the last time a package depending on them was built. These packages are then rebuilt when they are requested via straight-use-package. Normally, straight.el will try to detect what sort of find(1) program is installed, and issue the appropriate command. If it makes a mistake, then you can manually customize straight-find-flavor.

For about 100 packages on an SSD, calling find(1) to detect modifications takes about 500ms. You can save this time by customizing straight-check-for-modifications. This is a list of symbols which determines how straight.el detects package modifications. The default value is (find-at-startup find-when-checking), which means that find(1) is used to detect modifications at startup, and also when you invoke M-x straight-check-package or M-x straight-check-all. If you prefer to avoid this performance hit, or do not have find(1) installed, then you can remove these symbols from the list. In that case, you will probably want to add either check-on-save or watch-files to the list.

check-on-save causes straight.el to use before-save-hook to detect package modifications as you make them (modifications made by the straight.el repository management commands are also detected). This reduces init time, but modifications made outside of Emacs (or modifications that bypass before-save-hook) are not detected. Pull requests extending the number of cases in which straight.el is able to detect live modifications are welcome. Also, for the sake of efficiency, this form of modification checking is restricted to subdirectories of ~/.emacs.d/straight/repos, so you must put your local repositories into that directory for it to work. (Pull requests to change this would be welcome.)

watch-files causes straight.el to automatically invoke a filesystem watcher to detect modifications as they are made, inside or outside of Emacs. For this setting to work, you must have python3 and watchexec installed on your PATH. By default, the watcher persists after Emacs is closed. You can stop it manually by running M-x straight-watcher-stop, and start it again by running M-x straight-watcher-start. The watcher script is designed so that when one instance is started, all the others gracefully shut down, so you don't have to worry about accidentally ending up with more than one. There is nothing exciting in the process buffer for the watcher, but if you are interested in it then its name is given by straight-watcher-process-buffer. (By default, the name has a leading space so that the buffer does not appear in the buffer list.)

There is probably no good reason to use both check-on-save and watch-files at the same time. Your configuration can dynamically switch between which one is used depending on (executable-find "watchexec") or similar.

If you prefer to eschew automatic package rebuilding entirely, you can just set straight-check-for-modifications to nil. In that case, packages will only be rebuilt when metadata (e.g. the recipe or the Emacs version) changes, or when you manually invoke M-x straight-rebuild-package or M-x straight-rebuild-all.

Regardless of your preferred setting for straight-check-for-modifications, you should set it before the straight.el bootstrap snippet is run, since hooks relating to this variable are set during bootstrap.

On Microsoft Windows, find(1) is generally not available, so the default value of straight-check-for-modifications is instead (check-on-save).

Custom or manual modification detection

You can also use the low-level functions for modification detection directly.

The function straight-register-repo-modification takes a string (e.g. "straight.el") corresponding to the name of a local repository, and marks all packages from that local repository to be rebuilt at next Emacs startup. This function silently ignores local repositories which contain slashes, a limitation which might be removed in future.

The function straight-register-file-modification takes no arguments and checks if the file visited by the current buffer (if any) is contained by any local repository. If so, it delegates to straight-register-repo-modification. The check-on-save value for straight-check-for-modifications just adds straight-register-file-modification to before-save-hook.

Summary of options for package modification detection

`find-at-startup`

Save build timestamps and run find(1) at startup to detect changes

Most reliable, never misses changes
Requires find(1)
Slows down startup

`check-on-save`

Use before-save-hook to detect changes

No external dependencies
No startup delay
No additional CPU or memory impact
Doesn't catch changes made except via save-file inside Emacs

`watch-files`

Run filesystem watcher to detect changes

Requires Python 3 and Watchexec
No startup delay
Takes a few seconds to build virtualenv the first time
Memory and CPU impact of running filesystem watcher
Only misses changes if you make them after booting the system but before starting Emacs

Customizing how packages are built

By specifying a non-nil value for the :no-build attribute in a package's recipe, you may prevent the package from being built at all. This is usually useful for recipe repositories which do not bundle executable Lisp code. (Make sure to use straight-use-recipes for registering recipe repositories.)

By specifying a non-nil value for the :no-autoloads attribute in a package's recipe, you may prevent any autoloads provided by the package from being generated and loaded into Emacs. This is mostly useful if the package provides a large number of autoloads, you know you need only a few of them, and you wish to optimize your startup time (although this is almost certainly premature optimization unless you really know what you're doing). You can also customize the variable straight-disable-autoloads to effect this change on all recipes which do not explicitly specify a :no-autoloads attribute.

By specifying a non-nil value for the :no-byte-compile attribute in a package's recipe, you may inhibit byte-compilation. See this issue for discussion of why this might be useful. You can also customize the variable straight-disable-byte-compilation to effect this change on all recipes which do not explicitly specify a :no-byte-compile attribute.

Usually, straight.el uses symbolic links ("symlinks") to make package files available from the build directory. This happens when straight-use-symlinks is non-nil, the default. On Microsoft Windows, however, support for symlinks is not always available, so the default value of straight-use-symlinks is nil on that platform. That causes copying to be used instead, and an advice is placed on find-file to cause the copied files to act as symlinks if you try to edit them.

If you want to activate symlink-support on MS Windows 7, 8, or 10, you should ensure the following requirements:

straight-use-symlinks has to be set to non-nil manually.
Your user-account needs to be assigned the right to create symbolic links. To do so, run "secpol.msc" and in "Local Policies → User Rights Assignment" assign the right to "Create symbolic links" to your user-account.
If you have User Account Control (UAC) enabled and your user-account belongs to the the Administrators group you'll need to run Emacs in elevated mode to be able to create symlinks (see here and here and, for an official reference, section Access Token Changes in this document.
Windows Creators Update supports symlink-creation without any special permission setup.

Customizing how packages are made available

By setting the variable straight-cache-autoloads to a non-nil value, you can cause straight.el to cache the autoloads of all used packages in a single file on disk, and load them from there instead of from the individual package files if they are still up to date. This reduces the number of disk IO operations during startup from O(number of packages) to O(1), so it should improve performance. No other configuration should be necessary to make this work; however, you may wish to call straight-prune-build occasionally, since otherwise this cache file may grow quite large over time.

Hooks run by `straight-use-package`

Currently, straight-use-package supports two hooks:

straight-use-package-prepare-functions: The functions in this hook are run just before a package would be built, even if the package does not actually need to be rebuilt. They are passed the name of the package being (maybe) built as a string, and should take and ignore any additional arguments.
straight-use-package-pre-build-functions: The functions in this hook are run just before building a package (and only if the package needs to be built). They are passed the name of the package being built as a string, and should take and ignore any additional arguments.

The recipe format

The general format for a straight.el recipe is:

(package-name :keyword value :keyword value ...)

Note that if you wish to pass a recipe to straight-use-package, you will need to quote it. If you need to compute part of the recipe dynamically, use backquoting:

(straight-use-package
 `(el-patch :type git :repo ,(alist-get 'el-patch my-package-urls)))

Here is a comprehensive list of all keywords which have special meaning in a recipe (unknown keywords are ignored but preserved):

:local-repo

This is the name of the local repository that is used for the package. If a local repository by that name does not exist when you invoke straight-use-package, one will be cloned according to the package's version-control settings.

Multiple packages can use the same local repository. If so, then a change to the local repository will cause both packages to be rebuilt. Typically, if multiple packages are drawn from the same repository, both should specify a :files directive.

If you do not provide :local-repo, then it defaults to a value derived from the version-control settings, or as a last resort the package name.
:files

This is a list specifying which files in a package's local repository need to be symlinked into its build directory, and how to arrange the symlinks. For most packages, the default value (straight-default-files-directive) will suffice, and you do not need to specify anything.

If you do need to override the :files directive (this happens most commonly when you are taking a single package from a repository that holds multiple packages), it is almost always sufficient to just specify a list of globs or filenames. All matching files will be linked into the top level of the package's build directory.

In spite of this, the :files directive supports an almost comically powerful DSL (with nested excludes and everything!) that allows you full flexibility on how the links are made; see the docstring of straight-expand-files-directive for the full details.
:flavor

If this is non-nil, then it changes the interpretation of the :files directive for compatibility with an existing upstream recipe source. See the docstring of straight-expand-files-directive for details.
:no-build

If this is non-nil, then it causes the build step to be skipped entirely and unconditionally. You should specify this for recipe repository recipes.
:type

This specifies the version-control backend to use for cloning and managing the package's local repository. It defaults to the value of straight-default-vc, which defaults to git.

The only traditional version-control backend currently supported is git, although more backends may be added.

As a special case, however, you may specify the value built-in, which results in all version-control operations on the package being ignored. This allows you to tell straight.el that a package has already been provided (for example, because a version of it is shipped by Emacs) and does not have a local repository which needs to be cloned, updated, and so on. Here is how you can tell straight.el that you would like to use the Emacs-provided copy of Org, rather than cloning it from the upstream repository if another package declares it as a dependency:
```
(straight-use-package '(org :type built-in))
```
backend-specific keywords

Depending on the value of :type, additional keywords (relevant to how the package's repository is cloned and managed) will be meaningful. See the next section.

The built-in pseudo-backend does not take any other keywords.

Version-control backends

Defining a version-control backend consists of declaring a number of functions named as straight-vc-BACKEND-METHOD, where BACKEND is the name of the version-control backend being defined and METHOD is a backend API method. The relevant methods are:

clone: given a recipe and a commit object, clone the repository and attempt to check out the given commit.
commit-present-p: given a recipe and a commit object, return whether the commit can be checked out offline, i.e., without fetching from the remote.
normalize: given a recipe, "normalize" the repository (this generally means reverting it to a standard state, such as a clean working directory, but does not entail checking out any particular commit).
fetch-from-remote: given a recipe, fetch the latest version from its configured remote, if one is specified.
fetch-from-upstream: given a recipe, fetch the latest version from its configured upstream, if the package is forked.
merge-from-remote: given a recipe, merge the latest version fetched from the configured remote, if any, to the local copy.
merge-from-upstream: given a recipe, merge the latest version fetched from the configured upstream, if the package is forked, to the local copy.
push-to-remote: given a recipe, push the current version of the repository to its configured remote, if one is specified.
check-out-commit: given a recipe and a commit object, attempt to check out that commit in the repository for that recipe.
get-commit: given a local repository name, return the commit object that is currently checked out.
local-repo-name: given a recipe, return a good name for the local repository, or nil.
keywords: return a list of keywords which are meaningful for this version-control backend.

Most of these methods are highly interactive: they don't actually do anything without prompting you to confirm it, and very often they will offer you a number of different options to proceed (including starting a recursive edit and allowing you to do whatever you would like).

Also, all of the methods in this section take straight.el-style recipes; see the section on defining VC backends in the developer manual for more details.

Git backend

These are the keywords meaningful for the git backend:

:repo: the clone URL for the Git repository.
:host: either nil or one of the symbols github, gitlab, bitbucket. If non-nil, then :repo should just be a string "username/repo", and the URL is constructed automatically.
:branch: the name of the branch used for primary development, as a string. If your version lockfiles do not specify a commit to check out when the repository is cloned, then this branch is checked out, if possible. This branch is also viewed as the "primary" branch for the purpose of normalization and interaction with the remote.
:remote: the name to use for the Git remote. If the package is forked, this name is used for the upstream remote.
:nonrecursive: if non-nil, then submodules are not cloned. This is particularly important for the Emacsmirror recipe repository, which contains every known Emacs package in existence as submodules.
:fork: a plist which specifies settings for a fork, if desired. This causes the fetch-from-remote method to operate on the fork; you can use the fetch-from-upstream method to operate on the upstream instead. The allowed keywords are :repo, :host, :branch, and :remote.
:depth: either the symbol full or an integer. If full, then the repository is cloned with its whole history. If an integer N, then the repository is cloned with the option --depth N, unless a commit is specified (e.g. by version lockfiles). The default value is full.

This section tells you how the git backend, specifically, implements the version-control backend API:

clone: clones the repository, including submodules if :nonrecursive is not provided. Checks out the commit specified in your revision lockfile, or the :branch (from the :fork configuration, if given), or origin/HEAD. If a :fork is specified, also fetches from the upstream.
commit-present-p: checks if the commit SHA is among the revisions that are present locally.
normalize: verifies that remote URLs are set correctly, that no merge is in progress, that the worktree is clean, and that the primary :branch (from the :fork configuration, if given) is checked out.
fetch-from-remote: checks that remote URLs are set correctly, then fetches from the primary remote (the fork, if the package is forked).
fetch-from-upstream: checks that remote URLs are set correctly, then fetches from the upstream remote. If the package is not a fork, does nothing.
merge-from-remote: performs normalization, then merges from the primary remote (the fork, if the package is forked) into the primary local :branch.
merge-from-upstream: performs normalization, then merges from the upstream remote into the primary local :branch. If the package is not a fork, does not attempt to merge.
push-to-remote: performs normalization, pulls from the primary remote if necessary, and then pushes if necessary. This operation acts on the fork, if the package is forked.
check-out-commit: verifies that no merge is in progress and that the worktree is clean, then resets the worktree to the specified commit.
get-commit: returns HEAD as a 40-character string.
local-repo-name: if :host is non-nil, then :repo will be of the form "username/repository", and "repository" is used. Otherwise, if the URL is of the form .../<something>.git, then <something> is used. Otherwise, nil is returned.
keywords: see the list of keywords above.

You can customize the following user options:

straight-vc-git-default-branch: if :branch is unspecified, then this is used instead. Defaults to "master".
straight-vc-git-default-remote-name: the name to use for the primary remote, or the upstream remote if the package is forked. Defaults to "origin". The :remote keyword may be used to override the value of this variable on a per-repository basis.
straight-vc-git-default-fork-name: the name to use for the fork remote, if the package is forked. Defaults to "fork". The :remote keyword may be used to override the value of this variable on a per-repository basis.
straight-vc-git-default-protocol: the default protocol to use for automatically generated URLs when :host is non-nil. It can be either https or ssh, and defaults to https because this requires less work to set up.
straight-vc-git-force-protocol: if this is non-nil, then HTTPS and SSH URLs are not treated as equivalent, so that bulk version-control operations will offer to re-set your remote URLs from HTTPS to SSH or vice versa, depending on the value of straight-vc-git-default-protocol. This is nil by default.
straight-vc-git-auto-fast-forward: if this is non-nil, pulling will quietly do fast-forward, to suppress asking for instructions on each package with updates, unless they're not trivial. Set to nil if you'd prefer to inspect all changes.
straight-vc-git-default-clone-depth: the default value for the :depth keyword. It can be either the symbol full or an integer, and defaults to full. Setting this variable to a small integer will reduce the size of repositories. Note that this variable does not affect packages whose versions are locked.

Deprecated `:upstream` keyword

straight.el previously supported fork configuration in recipes using an :upstream keyword rather than a :fork keyword. For various reasons, this was more complex to handle, which is why the change was made. For backwards compatibility, the :upstream keyword is still accepted, with the following behavior.

When straight.el processes a recipe which uses the :upstream keyword, it moves the :repo, :host, and :branch keywords from that sub-plist to the top level, and moves those top-level keywords to a new :fork sub-plist. Then it sets the top-level and :fork sub-plist values of :remote to the values of the deprecated variables straight-vc-git-upstream-remote (defaults to "upstream") and straight-vc-git-primary-remote (defaults to "origin"), respectively.

For backwards compatibility, if straight-vc-git-primary-remote differs from its default value of "origin", then its value is used in place of straight-vc-git-default-remote-name.

Recipe lookup

If you only provide a symbol (package name) to straight-use-package, then the recipe is looked up automatically. By default, MELPA, GNU ELPA, and Emacsmirror are searched for recipes, in that order. This means that one or more of them may need to be cloned. Recipe repositories are actually just the same as ordinary packages, except that their recipes specify :no-build, so they are not symlinked or added to the load-path or anything.

Note that dependencies always use the default recipes, since the only information straight.el gets about a package's dependencies are their names.

This leads to a few interesting questions regarding requesting a package multiple times. For example, you might need to load two features using use-package that are provided from the same package, or one of the packages you have installed is also requested as a dependency by another package. straight.el uses a number of heuristics to try to make these interactions as intuitive and painless as possible:

The first time a package is registered with straight.el, its recipe (either the recipe that you provided, or the one that was looked up from a recipe repository) is recorded. In future registration, if you just provide the package name to straight-use-package, the existing recipe is reused.

Note, however: if you want to use a custom recipe for a given package, you must load it before all of its dependencies. Otherwise, the package will first be registered as a dependency, using the default recipe.
If a package has already been registered with straight.el, and you attempt to load it again with an explicit recipe which is different from the one previously registered, the new recipe is used but a warning is signalled.
If you attempt to register a package which shares a :local-repo (either by default, or due to explicit specification) with a previously registered package, and the two packages specify different values for their version-control keywords (see version-control backends), then the new recipe is used but a warning is signalled. If the repository was already cloned, this means the second recipe will have no effect.

But if the second recipe was fetched automatically from a recipe repository, all of its version-control keywords will be silently overwritten with the ones from the first recipe, to avoid conflicts (although if there are conflicts in other parts of the recipe, a warning will still be displayed).

Updating recipe repositories

As mentioned in the conceptual overview, recipe repositories are just regular packages, with some extra code to look up recipes in the relevant local repository.

This means that updating a recipe repository is done the same way as updating a regular package, i.e. with M-x straight-pull-package. You should do this if you find that a package isn't listed by M-x straight-use-package—perhaps it was added recently.

Note that there is currently some potentially surprising behavior if you update all packages at once using M-x straight-pull-all or M-x straight-merge-all, and this bulk update includes recipe repository updates: see #323.

Customizing recipe repositories

The recipe repository system is designed to be extended. Firstly, you can control which recipe repositories are searched, and in what order of precedence, by customizing straight-recipe-repositories. The default value is:

(org-elpa melpa gnu-elpa-mirror emacsmirror)

GNU ELPA

You can customize the following user options:

straight-recipes-gnu-elpa-url: The Git URL to use for the gnu-elpa recipe repository.
straight-recipes-gnu-elpa-use-mirror: GNU ELPA uses a stupidly complex build system for no good reason, and it's unlikely to change any time soon. What this means for you is that you have to run the Elisp-powered Makefile of the GNU ELPA repository (which has a fatal bug last I checked, so you'd have to patch it locally) and have a full checkout of the Emacs source repository (more than 1GB) if you want all the packages to work correctly. To work around this problem, I maintain a full mirror of GNU ELPA on GitHub. (The tooling used to maintain this mirror is located here.) By default, straight.el retrieves packages from this mirror instead of the source repository; this behavior is controlled by the value of straight-recipes-gnu-elpa-use-mirror. You must do any customization of this variable before the straight.el bootstrap. Note that setting the value of this user option to nil causes the default value of straight-recipe-repositories to shift to:
```
(org-elpa melpa gnu-elpa emacsmirror)
```

Emacsmirror

You can customize the following user option:

straight-recipes-emacsmirror-use-mirror: Yes, there is also a mirror for Emacsmirror. This is because the epkgs repository contains a (frequently updated) SQLite database in it, which means the Git repository takes forever to clone (see #356). My solution to this problem is to generate a new repository which contains the information that straight.el needs but which is much smaller. By default, straight.el uses the official epkgs repository to find packages on Emacsmirror, but you can tell it to use my mirror by configuring the value of this variable to non-nil. You must do any customization of this variable before the straight.el bootstrap. Note that setting the value of this user option to non-nil causes the default value of straight-recipe-repositories to shift to:
```
(org-elpa melpa gnu-elpa-mirror emacsmirror-mirror)
```

Defining new recipe repositories

To define a new recipe repository called NAME, you should do the following things:

Define a function straight-recipes-NAME-retrieve, which takes a package name as a symbol and returns a recipe for that package if it is available, else nil. This is used for recipe lookup. This function may assume that the local repository for the recipe repository has already been cloned, and that default-directory has been set to that local repository. This is used for recipe lookup during the course of straight-use-package.
Define a function straight-recipes-NAME-list, which takes no arguments and returns a list of strings representing packages for which recipes are available. It is permissible to return some strings for which recipes are actually not available, for performance reasons. However, this is discouraged. (The MELPA backend uses this functionality, since all files in the recipes directory are potentially recipes, but only the Git-based ones can actually be used.)
(Optional) Define a function straight-recipes-NAME-version which returns a non-nil value indicating the current version of the logic in your straight-recipes-NAME-retrieve function. Each time you change the logic, this version value must be changed. If this function is defined, then straight.el automatically and transparently caches calls to straight-recipes-NAME-retrieve persistently, using your version value (and its detection of modifications to the recipe repository) to decide when to invalidate the cache.
Call straight-use-recipes with the recipe for your recipe repository. Make sure to include :no-build in the recipe, unless you also want to use the recipe repository as an executable Emacs Lisp package. Alternatively, you can take the manual approach:
- Call straight-use-package-lazy with the recipe for your recipe repository.
- Add the symbol for your recipe repository's name (the car of the recipe you provided, that is) to straight-recipe-repositories, at the appropriate place.

Overriding recipes

You can always use straight-register-package to specify a specific recipe for a package without cloning or building it, so that just in case that package is requested later (possibly as a dependency, or in somebody else's code) your recipe will be used instead of the default one. However, this does not help in the case that a specific recipe is passed to straight-use-package.

Also, it is obviously impossible to call straight-register-package before straight.el has been loaded, so you can't use it to specify a custom recipe for straight.el itself.

To remedy these difficulties, straight.el provides a mechanism for specifically overriding the recipe for a particular package. You can use it by customizing straight-recipe-overrides, or by calling straight-override-recipe.

straight-recipe-overrides is an association list from profile names to override alists. If you don't care about the profile system, you can just use a single override specification, with the profile name nil. Each override alist is just a list of recipes. Because the car of a recipe is just the package name as a symbol, this list of recipes is also an alist whose keys are recipe names and whose values are the plists for those recipes.

Even if an explicit recipe is supplied to straight-use-package, the one given in straight-recipe-overrides will be used instead, if such a recipe is specified there.

For convenience, you may add to straight-recipe-overrides by passing a recipe to straight-override-recipe. This will register it in the override alist for the current profile. Note that if you do this, you will probably want to explicitly set straight-recipe-overrides to nil before bootstrapping straight.el. This will make it so that if you remove a call to straight-override-recipe from your init-file and then reload it, the entry will actually be removed from straight-recipe-overrides.

Overriding the recipe for `straight.el`

As was briefly mentioned earlier, you can actually override the recipe of straight.el itself using straight-recipe-overrides! How does this work? Well, it's basically black magic. If you want the details, go read the developer manual. All you need to know is that you can set straight-recipe-overrides, and it will magically work. The only caveat is that if you change the :local-repo for straight.el, then you will also need to adjust the value of bootstrap-file in the bootstrap snippet accordingly, since otherwise your init-file will not know where to find straight.el. (You must use straight-recipe-overrides instead of straight-override-recipe, since the latter function definition hasn't been loaded yet before straight.el is installed and bootstrapped.)

Here is the default recipe used for straight.el, if you don't override it:

(straight :type git :host github
          :repo ,(format "%s/straight.el" straight-repository-user)
          :files ("straight*.el")
          :branch ,straight-repository-branch)

Note that even though the bootstrap snippet references the develop branch of straight.el, the default recipe installs from master.

If all you want to do is change which branch you are installing straight.el from, simply customize the variable straight-repository-branch, which is provided for this purpose. (Although using straight-recipe-overrides will work just as well, at least until the recipe happens to be changed upstream and your init-file isn't updated.)

Similarly, if all you want to do is switch to your own fork of straight.el on GitHub, simply customize the variable straight-repository-user to your GitHub username.

There is one minor caveat to the above discussion. If your fork makes changes to the way in which recipes are interpreted, then those changes will not be effective during the interpretation of your own recipe for straight.el. If you wish for them to be, then you will have to follow the same procedure that is followed in straight.el itself for making changes to recipe interpretation. These details are outlined in the developer manual; see also install.el for an explanation of this aspect of the bootstrap mechanism.

Interactive usage

The primary usage of straight.el is expected to be in your init-file. For example, this is where you will need to put the bootstrap code as well as any packages that you always want to be installed. However, there are three important interactive uses of straight.el: temporary installation of packages, various helpful utility functions, and version control operations.

To install a package temporarily, run M-x straight-use-package. All registered recipe repositories will be cloned, and you will be presented with a combined list of all recipes available from them. Simply select a package and it will be cloned, built, and loaded automatically. This does not affect future Emacs sessions.

If you provide a prefix argument to M-x straight-use-package, then you are presented with a list of registered recipe repositories. After you select one, you are shown a list of recipes specifically from that recipe repository. This is helpful if you do not want to clone all registered recipe repositories, or you have a particular recipe repository in mind.

You can also call M-x straight-get-recipe, which has the same interface as M-x straight-use-package, except that instead of the package being cloned, built, and loaded, its recipe is copied to the kill ring. If you are writing a custom recipe, this may be helpful, because you may be able to reuse parts of the existing recipe, particularly the :files directive.

Normally, packages are rebuilt automatically if needed, when Emacs restarts. If you for some reason want them to be rebuilt at another time, you can call M-x straight-check-all to rebuild all packages that have been modified since their last build. Alternatively, use M-x straight-rebuild-all to unconditionally rebuild all packages. Note that this will probably take a while. There are also M-x straight-check-package and M-x straight-rebuild-package, which allow you to select a particular package to check or rebuild.

Finally, you may use M-x straight-prune-build in order to tell straight.el to forget about any packages which were not registered since the last time you loaded your init-file. This may improve performance, although only slightly, and will clean up stale entries in the build directory. You can call this function in your init-file if you really wish your filesystem to be as clean as possible, although it's not particularly recommended as the performance implications are uninvestigated. If you do call it in your init-file, be sure to only call it on a fully successful init; otherwise, an error during init will result in some packages' build information being discarded, and they will need to be rebuilt next time.

If you have enabled autoloads caching, it is advisable to call straight-prune-build occasionally, since otherwise the build cache may grow quite large over time.

Version control operations

straight.el provides a number of highly interactive workflows for managing your package's local repositories, using the configured version-control backends. They are as follows:

M-x straight-normalize-package: normalize a package
M-x straight-normalize-all: normalize all packages
M-x straight-fetch-package: fetch from a package's configured remote; with prefix argument, then for forks also fetch from the upstream
M-x straight-fetch-package-and-deps: fetch from the configured remotes of a package and all of its dependencies (including the dependencies of its dependencies); with prefix argment, then for forks also fetch from the upstream
M-x straight-fetch-all: fetch from all packages' configured remotes; with prefix argument, then for forks also fetch from the upstreams
M-x straight-merge-package: merge the latest version fetched from a package's configured remote into the local copy; with prefix argument, then for forks also merge from the upstream
M-x straight-merge-package-and-deps: merge the latest versions fetched from the configured remotes of a package and all of its dependencies (including the dependencies of its dependencies); with prefix argment, then for forks also merge from the upstreams
M-x straight-merge-all: merge the latest versions fetched from each package's configured remote into its local copy; with prefix argument, then for forks also merge from the upstreams
M-x straight-pull-package: combination of M-x straight-fetch-package and M-x straight-merge-package
M-x straight-pull-package-and-deps: combination of M-x straight-fetch-package-and-deps and M-x straight-merge-package-and-deps
M-x straight-pull-all: combination of M-x straight-fetch-all and M-x straight-merge-all
M-x straight-push-package: push a package to its remote, if necessary
M-x straight-push-all: push all packages to their remotes, if necessary

See the sections on version-control backends and the Git backend in particular for more information about the meanings of these operations.

Lockfile management

straight.el determines your package management configuration from two, and only two, sources: the contents of your init-file, and your version lockfiles (which are optional). Your init-file specifies the configuration of straight.el (for example, the values of straight-recipe-overrides and straight-default-vc), the packages you want to use, and their recipes. Your version lockfiles specify the exact revisions of each package, recipe repository, and even straight.el itself. Together, they lock down your Emacs configuration to a state of no uncertainty: perfect reproducibility.

To write the current revisions of all your packages into version lockfiles, run M-x straight-freeze-versions. This will first check that straight.el has an up-to-date account of what packages are installed by your init-file, then ensure that all your local changes are pushed (remember, we are aiming for perfect reproducibility!). If you wish to bypass these checks, provide a prefix argument.

Version lockfiles are written into ~/.emacs.d/straight/versions. By default, there will be one, called default.el. It is recommended that you keep your version lockfiles under version control with the rest of your Emacs configuration. If you symlink your init-file into ~/.emacs.d from somewhere else, you should also make sure to symlink your version lockfiles into ~/.emacs.d/straight/versions. On a new machine, do this before launching Emacs: that way, straight.el can make sure to check out the specified revisions of each package when cloning them for the first time.

To install the versions of the packages specified in your version lockfiles, run M-x straight-thaw-versions. Thawing will interactively check for local changes before checking out the relevant revisions, so don't worry about things getting overwritten.

The profile system

straight.el has support for writing multiple version lockfiles, instead of just one. Why? Consider a large Emacs configuration such as Radian, Spacemacs, or Prelude, which is used by many different people. There are two parts to the configuration that is actually loaded: the "default" part, and the local customizations that each user has added. Generally, these configurations have a mechanism for making local customizations without forking the entire project.

So Radian will have some set of packages that it requires, and my local customizations of Radian have some other set of packages that they require. In order for me to maintain Radian, I need to be able to separate Radian's packages (which go into a versions lockfile in the Radian repository) from my own local packages (which go into a versions lockfile in my own private local dotfiles repository). straight.el provides this ability through the profile system.

The idea is that whenever a package is registered, either directly or as a dependency, it is associated with a given profile. Any given package can be associated with multiple profiles.

When you call straight-use-package, which profile the registered packages are associated with is determined by the value of straight-current-profile, which defaults to nil. In Radian, for example, straight-current-profile is bound to radian while the Radian libraries are being loaded, and it is bound to radian-local while the user's local customizations are being loaded. This results in Radian packages being associated with the radian profile, and the user's local packages being associated with the radian-local profile.

When you call M-x straight-freeze-versions, one or more version lockfiles are written, according to the value of straight-profiles. This variable is an association list whose keys are symbols naming profiles and whose values are filenames for the corresponding version lockfiles to be written into ~/.emacs.d/straight/versions. You should make sure that each potential value of straight-current-profile has a corresponding entry in straight-profiles, since otherwise some packages might not be written into your lockfiles.

When customizing straight-recipe-overrides, note that if multiple profiles are set to override the same recipe, then the last one listed in straight-profiles will take precedence. Similarly, when using M-x straight-thaw-versions, if different lockfiles specify revisions for the same local repository, the last one in straight-profiles will take precedence.

Packages and the init-file

Package managers like package.el store mutable state outside your init-file, including the set of packages that are installed. straight.el does not do this, so it has a rather different way of determining what packages are installed. To straight.el, a package is part of your Emacs configuration if it is passed to straight-use-package when your init-file is loaded.

Note that this means packages installed interactively (using M-x straight-use-package) are not considered part of your Emacs configuration, since the invocation of straight-use-package does not happen in your init-file.

This raises an interesting question: if you add a package to your init-file, how can you convince straight.el that it really is part of your init-file, and not just part of a temporary straight-use-package form that you evaluated ad-hoc? The answer is simple: reload your entire init-file. That way, straight.el will see whether or not that package is registered during your init-file.

One might ask how straight.el determines that you have finished loading your init-file. The answer is simple: run-with-idle-timer is used to execute code only after the current interactive operation has finished. The implementation of this concept is part of the transaction system of straight.el, and it is also used to amortize certain performance costs when many calls to straight-use-package are made sequentially. However, since the transaction system (at least in recent versions of straight.el) operates transparently, its details are relegated to the developer manual.

Using `straight.el` to reproduce bugs

One of the major reasons I wanted to write straight.el was that existing package managers were not good for reproducing bugs. For instance, some of them would load all installed packages when the package manager was initialized! Obviously that is not acceptable for a "minimal test case".

On the contrary, bootstrapping straight.el does not load anything except for straight.el itself (the default recipe repositories are registered, but not cloned until needed). You should normally be loading straight.el by means of the bootstrap snippet, but when you are in emacs -Q, here is how you can initialize straight.el:

M-x load-file RET ~/.emacs.d/straight/repos/straight.el/bootstrap.el RET

You can also do this from the command line, perhaps by creating an alias for it:

$ emacs -Q -l ~/.emacs.d/straight/repos/straight.el/bootstrap.el

Let's say you are making a bug report for Projectile. To load just Projectile and all of its dependencies, run:

M-x straight-use-package RET projectile RET

Note that this will use the currently checked-out revisions of Projectile and all of its dependencies, so you should take note of those in order to make your bug report.

Integration with other packages

Integration with `use-package`

By default, straight.el installs a new keyword :straight for use-package which may be used to install packages via straight.el. The algorithm is extremely simple. This:

(use-package el-patch
  :straight t)

macroexpands (essentially) to:

(straight-use-package 'el-patch)

And this:

(use-package el-patch
  :straight (:host github :repo "raxod502/el-patch"
             :branch "develop"))

becomes:

(straight-use-package
 '(el-patch :host github :repo "raxod502/el-patch"
            :branch "develop"))

If the feature you are requiring with use-package is different from the package name, you can provide a full recipe:

(use-package tex-site
  :straight (auctex :host github
                    :repo "emacsmirror/auctex"
                    :files (:defaults (:exclude "*.el.in"))))

And you may also provide just the package name:

(use-package tex-site
  :straight auctex)

If you don't provide :straight, then by default nothing happens. You may customize straight-use-package-by-default to make it so that :straight t is assumed unless you explicitly override it with :straight nil.

Previously, straight.el used a different syntax for its use-package integration. For backwards compatibility, you can use this syntax instead by customizing straight-use-package-version.

You can disable use-package integration entirely by customizing straight-enable-use-package-integration.

"Integration" with `package.el`

By default, package.el will automatically insert a call to package-initialize into your init-file as soon as Emacs starts, which is ridiculous. It will also do this when you perform any package management operation. A separate system inserts some custom forms into your init-file when you install a package. straight.el disables all of these "features" by setting package-enable-at-startup to nil and enabling some advices. You can override this behavior by customizing straight-enable-package-integration, however.

Integration with Org

Org expects you to run make in its source repository before you run it, but straight.el does not yet support running such build systems automatically (see #72). This presents two problems:

Byte-compiling Org without running make first produces some annoying warnings.
Running make generates a file org-version.el which provides the functions org-git-version and org-release. Thus the version of Org provided by straight.el does not include these functions, but the obsolete version of Org provided by Emacs (see the FAQ) does. This can result in the obsolete version getting partially loaded, which is confusing.

See #211 for discussion.

By default, straight.el installs a hack (namely, defining the functions org-git-version and org-release itself) whenever you ask it to install Org. This functionality is implemented using straight-use-package-prepare-functions. You can disable it by setting the value of the variable straight-fix-org to nil.

Integration with Hydra

See the Hydra wiki.

Miscellaneous

By default, straight.el explains what it is doing in the echo area, like this:
```
Looking for cider recipe → Cloning melpa...
```
If your terminal does not support Unicode characters nicely, you can customize straight-arrow to display something else for the arrow.
By default, straight.el reports process output the *straight-process* buffer. You can customize the name of this buffer via the straight-process-buffer user option. If you want to hide this buffer by default, consider adding a leading space to the name.
You can prevent straight.el from making any modifications to the filesystem (though it may still read) by customizing the user option straight-safe-mode to non-nil. This may be useful for running tasks automatically in batch mode, to avoid multiple concurrent Emacs processes all making changes to the filesystem. For an example of how this feature may be used to safely implement asynchronous byte-compilation of the init-file on successful startup, see Radian.

Developer manual

This section tells you about all the interesting implementation details and design decisions that power straight.el behind the scenes. It assumes you have already read the user manual and the conceptual overview.

Unfortunately, I haven't yet had time to write it. See #51.

Trivia

This section has random, (possibly) interesting tidbits about straight.el that don't fit in the other sections.

Comments and docstrings

How did I get that statistic about the percentage of straight.el that is comments and docstrings? Simple: by abusing the syntax highlighting.

(let ((lines (make-hash-table :test #'equal)))
  (goto-char (point-min))
  (while (< (point) (point-max))
    (when (memq (face-at-point)
                '(font-lock-comment-face
                  font-lock-doc-face))
      (puthash (line-number-at-pos) t lines))
    (forward-char))
  (* (/ (float (length (hash-table-keys lines)))
        (line-number-at-pos))
     100))

Note that you will have to scroll through the entire buffer first, since font-lock-mode computes syntax highlighting lazily.

Contributing

Please do! Development takes place on the develop branch. You can switch to that branch with

(setq straight-repository-branch "develop")

and base your pull requests from it. If you have an outstanding pull request whose features you would like to use in your configuration, there is full support for defining straight.el as coming from any branch in any fork:

(setq straight-repository-user "my-github-username")
(setq straight-repository-branch "feat/my-cool-feature")

Please try to follow the style of the surrounding code and documentation, but anything is welcome.

You can run the linting locally simply by running

$ make

(although first you should make sure there is a suitable emacs binary on your path, and you have installed markdown-toc).

FAQ

My init time got slower

Your first step should be to customize the value of straight-check-for-modifications. The best setting is (watch-files find-when-checking); this is not enabled by default because it is impolite to spawn persistent background processes without asking, and because you must install Python 3 and watchexec for it to work. If you can't stand the extra dependencies and background process, consider the setting (check-on-save find-when-checking) instead, which is just as fast but won't catch package modifications unless they are made within Emacs via the save-buffer command.

Even with lazy modification detection, as described above, straight.el is not quite as fast as package.el (by a few percentage points). There are some planned changes which will make straight.el just as fast as package.el, if not faster. See #9.

How do I update MELPA et al.?

Using M-x straight-pull-package, like for any other package. Read more.

The wrong version of my package was loaded

To explain this problem, let us consider a concrete example. In this issue, a user found that the code

(straight-use-package 'company-lsp)
(straight-use-package 'eglot)

sometimes resulted in runtime errors because an old version of Flymake was being used.

The root problem here is that you want the most recent version of Flymake to be installed by straight.el, but Emacs also ships an older version, and that older version is getting loaded instead.

The older version will be loaded if (require 'flymake) (or similar) is invoked before straight.el has made Flymake available (by means of (straight-use-package 'flymake) or similar). But why would straight.el not make Flymake available?

The only way that straight.el knows to make Flymake available is if either you manually invoke straight-use-package in your init-file, or if one of the packages that you request in your init-file declares Flymake as a dependency. Now, any package that uses Flymake ought to declare it as a dependency. Thus, there should be no way for a package to load the Emacs-provided version of Flymake. However, sometimes package authors overlook this problem (it does not always cause an error, and sometimes package authors do not test exhaustively enough).

In this case, the problem was that company-lsp declared a dependency on lsp-mode, and lsp-mode used Flymake without declaring a dependency on flymake. There are two ways to work around the problem:

(Preferable) Fix lsp-mode to declare a dependency on flymake.
(Workaround) Manually invoke (straight-use-package 'flymake) before (straight-use-package 'company-lsp).

If you test this yourself, you might find it difficult to reproduce the problem. That is because there is only an issue when Flymake is actually loaded, and this doesn't necessarily happen when invoking (straight-use-package 'company-lsp) unless straight.el needs to rebuild the relevant packages (which includes byte-compilation, which sometimes means actually loading dependencies). Keep this in mind when testing.

This problem commonly occurs with Org, since (1) Org is popular, (2) Emacs ships an obsolete version of Org, (3) many users want to use the up-to-date version, and (4) Org breaks backwards compatibility frequently. To solve it, simply make sure that you invoke (straight-use-package 'org) or (straight-use-package 'org-plus-contrib) before running any code that could load Org, including installing any package that lists it as a dependency. See also the integration with Org section for more fun problems you can encounter with Org.

See this issue for discussion about ways of mitigating the bad UX of this situation.

I get "could not read username/password" errors

This is because straight.el is not currently able to detect when SSH or Git asks for your username and/or password/passphrase and then pipe that prompt through to the minibuffer (#334).

To work around the problem, set up git-credential-cache if you use HTTPS, and ssh-agent if you use SSH. That way, you won't be prompted for your username/password. When setting up ssh-agent, be careful to make sure that the relevant environment variables get set in Emacs. This might be tricky since starting Emacs from the desktop (rather than from the command line) sometimes results in it not inheriting any environment variables from your shell.

The interactive version-control operations are confusing

This part of straight.el still needs some work; see #54 about the UX of pushing and pulling.

How do I pin package versions or use only tagged releases?

This is a planned feature. In the meantime, contributors have proposed various workarounds. See #246 and #31.

straight-x.el now contains an experimental solution. In order to use it you will need to add similar snippets to your Emacs configuration.

First you need to add a new profile to straight-profiles which also needs to be the last profile in the list. This should be done before you bootstrap straight.el.

;; Tell straight.el about the profiles we are going to be using.
(setq straight-profiles
      '((nil . "default.el")
        ;; Packages which are pinned to a specific commit.
        (pinned . "pinned.el")))

After straight's install procedure you will need to add straight-x.el and load the required commands.

(autoload #'straight-x-pull-all "straight-x")
(autoload #'straight-x-freeze-versions "straight-x")

A variable called straight-x-pinned-packages has been defined in straight-x.el and will contain your list of pinned packages.

From now on, you can pin a package to a specific commit like in the following example which will pin org-mode to the 9.2.3 release version:

(let ((straight-current-profile 'pinned))
  (straight-use-package 'org-plus-contrib)
  (straight-use-package 'org)
  ;; Pin org-mode version.
  (add-to-list 'straight-x-pinned-packages
               '("org" . "924308a150ab82014b69c46c04d1ab71e874a2e6")))

If you invoke straight-x-freeze-versions it will first write the default lockfile and then pinned lockfile which takes precedence over the default one if packages are thawed. straight-x-pull-all will first invoke straight-pull-all and then restore all pinned packages.

You might want to assign the following aliases for more convenience:

(defalias 'straight-pull-all #'straight-x-pull-all)
(defalias 'straight-freeze-versions #'straight-x-freeze-versions)

Please keep in mind that this is only a temporary solution and experimental!

How can I use the built-in version of a package?

To tell straight.el that you want to use the version of Org shipped with Emacs, rather than cloning the upstream repository:

(straight-use-package '(org :type built-in))

News

July 6, 2019

The default value of the user option straight-emacsmirror-use-mirror is now non-nil.

May 24, 2019

I have completely rewritten the transaction system. The practical impact of this is that you no longer have to care about it. Simply remove all references to the following functions and variables from your configuration, and everything should "just work":

straight-transaction
straight-begin-transaction
straight-finalize-transaction
straight-mark-transaction-as-init
straight-treat-as-init

May 22, 2019

I now maintain a mirror of Emacsmirror. (Bear with me here.) The advantage of using my mirror is that cloning it is several orders of magnitude faster than cloning the official Emacsmirror. You can tell straight.el to do so by customizing the user option straight-emacsmirror-use-mirror to non-nil.

May 1, 2019

straight-thaw-versions now fetches in a repository if a commit in your lockfile can not be found and normalizes the repository to the recipe's default branch. This should ensure that versions you have frozen can be quickly restored and that they can also be saved back to the version lock file. This addresses issues #58, [#66], and [#294].

March 15, 2019

straight.el now installs a hack for Org by default, so Org should work out of the box with no compile warnings. If you have code to work around the problem in your init-file, you can safely remove it. To avoid installing the hack, customize the variable straight-fix-org.

December 22, 2018

The default value of the user option straight-recipes-gnu-elpa-use-mirror is now non-nil.

September 12, 2018

straight.el now supports specifying configuration for your fork of a package via the new :fork keyword. The previously supported :upstream keyword is now deprecated, but still works for backwards compatibility. To support this change, the user options straight-vc-git-primary-remote and straight-vc-git-upstream-remote are deprecated (but still work for backwards compatibility), as they have been superseded by the new user options straight-vc-git-default-remote-name and straight-vc-git-default-fork-name. Your usage should be updated.

July 19, 2018

straight.el now automatically caches the recipes it looks up in recipe repositories. This should lead to a reduction in straight.el-related startup time of as much as 50% if you also use live modification detection, as disk IO and usage of external processes are reduced significantly.

No changes to user configuration are necessary; however, if you define a custom recipe repository (call it NAME) then caching is not enabled by default. To enable caching, define a straight-recipes-NAME-version function which returns a non-nil value indicating the current version of the logic in straight-recipes-NAME-retrieve. This version value needs to be changed each time you change the logic, so that the recipe lookup cache for that recipe repository may automatically be invalidated.

July 12, 2018

I now maintain a full mirror of GNU ELPA on GitHub. You can tell straight.el to use it by customizing the user option straight-recipes-gnu-elpa-use-mirror, and this will allow you to use packages such as AUCTeX correctly, which was previously impossible. Note that the user option must be customized before the straight.el bootstrap.

dajva/straight.el

Features

Guiding principles

Getting started

Debugging

Install packages

But what about my fork of (obscure .el package)?

Integration with use-package

Edit packages locally

Automatic repository management

Configuration reproducibility

Conceptual overview

TL;DR

What is a package?

Where do packages come from?

What does this look like on disk?

Where do repositories come from?

What does it mean to load a package?

Where do recipes come from?

What happens when I call straight-use-package?

What does it mean to register a package?

How does straight.el know when to rebuild packages?

How does straight.el know what packages are installed?

Comparison to other package managers

TL;DR

Comparison to package.el

Advantages of straight.el

Advantages of package.el

Additional notes

Comparison to Quelpa

Advantages of straight.el

Advantages of Quelpa

Additional notes

Comparison to Cask

Advantages of straight.el

Advantages of Cask

Comparison to el-get

Advantages of straight.el

Advantages of el-get

Comparison to Borg

Advantages of straight.el

Advantages of Borg

Comparison to the manual approach

Advantages of straight.el

Advantages of the manual approach

User manual

Bootstrapping straight.el

Installing packages programmatically

Installing with a custom recipe

Additional arguments to straight-use-package

Variants of straight-use-package

Customizing when packages are built

Custom or manual modification detection

Summary of options for package modification detection

find-at-startup

check-on-save

watch-files

Customizing how packages are built

Customizing how packages are made available

Hooks run by straight-use-package

The recipe format

Version-control backends

Git backend

Deprecated :upstream keyword

Recipe lookup

Updating recipe repositories

Customizing recipe repositories

GNU ELPA

Emacsmirror

Defining new recipe repositories

Overriding recipes

Overriding the recipe for straight.el

Interactive usage

Version control operations

Lockfile management

The profile system

Packages and the init-file

Using straight.el to reproduce bugs

Integration with other packages

Integration with use-package

Integration with `use-package`

What happens when I call `straight-use-package`?

How does `straight.el` know when to rebuild packages?

How does `straight.el` know what packages are installed?

Comparison to `package.el`

Advantages of `straight.el`

Advantages of `package.el`

Advantages of `straight.el`

Advantages of `straight.el`

Advantages of `straight.el`

Advantages of `straight.el`

Advantages of `straight.el`

Bootstrapping `straight.el`

Additional arguments to `straight-use-package`

Variants of `straight-use-package`

`find-at-startup`

`check-on-save`

`watch-files`

Hooks run by `straight-use-package`

Deprecated `:upstream` keyword

Overriding the recipe for `straight.el`

Using `straight.el` to reproduce bugs

Integration with `use-package`

"Integration" with `package.el`