mcwitt/reproducible-figure

Example of reproducible TeX/TikZ figure using Nix

TikZ reproduction of the linked sketch.

The result looks like

Environment setup using Nix

Use Nix to set up a reproducible environment for editing this figure. Note that the first time these commands are run, there may be a significant delay if the dependencies (e.g. TeXLive) need to be downloaded and built.

Building from scratch

nix-build

The output PDF is created in ./result.

Editing

nix-shell

This drops you into a shell environment with the necessary dependencies. E.g. you can then run

pdflatex figure.tex

to rebuild the figure after editing the TeX code.

Explanation of Nix files

• default.nix is the entry point for the nix-build and nix-shell commands. It imports the environment nixpkgs version and calls package.nix. Note: this method is not fully reproducible because the environment may define a different revision of nixpkgs than we used in the original build. For full reproducibility, use release.nix instead (this pins the version of nixpkgs).

• package.nix takes as input some nixpkgs repository and contains the actual build instructions. In this case, we can use the texFunctions.runLaTeX helper, so the only work to be done is to specify the additional packages we depend on.

• release.nix is the entry point for reproducible builds. That is, it serves the same purpose as default.nix, but pins the version of nixpkgs that is used to build the environment (the pinned version is specified in nixpkgs.json). This can be used with nix-build and nix-shell by passing it as an arugment, e.g. nix-build release.nix.

• nixpkgs.json specifies the revision of the nixpkgs repository used for the reproducible build. It is imported by release.nix