Couldn't install on Mac OSX High Sierra 10.13.5

[willsheppard]

I got errors when trying to install.

Brew installed:

brew --version
Homebrew 1.7.1
Homebrew/homebrew-core (git revision 0ce9; last commit 2018-07-24)

Haskell installed okay:

$ brew install haskell-stack
==> Downloading https://homebrew.bintray.com/bottles/haskell-stack-1.7.1.high_sierra.bottle.tar.gz
==> Downloading from https://akamai.bintray.com/fd/fda2391548b3ff62866e09f584458fa7e4b894273c77024134a99f90b56850e6?__gda__=exp=153242
######################################################################## 100.0%
==> Pouring haskell-stack-1.7.1.high_sierra.bottle.tar.gz
🍺  /usr/local/Cellar/haskell-stack/1.7.1: 6 files, 38MB

git-mediate didn't go so well:

$ stack install git-mediate
Writing implicit global project config file to: /Users/will/.stack/global-project/stack.yaml
Note: You can change the snapshot via the resolver field there.
Using latest snapshot resolver: lts-12.2
Downloaded lts-12.2 build plan.    
Preparing to install GHC to an isolated location.
This will not interfere with any system-level installation.
Downloaded ghc-8.4.3.                                      
Installed GHC.                                                               
Selected mirror https://s3.amazonaws.com/hackage.fpcomplete.com/                                 
Downloading root                                                                                 
Selected mirror https://s3.amazonaws.com/hackage.fpcomplete.com/                                 
Downloading timestamp                                                                            
Downloading snapshot                                                                             
Downloading mirrors                                                                              
Cannot update index (no local copy)                                                              
Downloading index                                                                                
Updated package index downloaded                                                                 
Update complete                                                                                  
Populated index cache.    

Error: While constructing the build plan, the following exceptions were encountered:

In the dependencies for git-mediate-1.0.3:
    base-compat-0.10.4 from stack configuration does not match >=0.8.2 && <0.10  (latest matching version is 0.9.3)
needed since git-mediate is a build target.

Some different approaches to resolving this:

  * Set 'allow-newer: true' to ignore all version constraints and build anyway.

  * Consider trying 'stack solver', which uses the cabal-install solver to attempt to find some working build configuration. This can
    be convenient when dealing with many complicated constraint errors, but results may be unpredictable.

  * Recommended action: try adding the following to your extra-deps in /Users/will/.stack/global-project/stack.yaml:

- base-compat-0.9.3

Plan construction failed.

I tried to follow the instructions but I have no experience of haskell stack:

$ vi /Users/will/.stack/global-project/stack.yaml
$ cat /Users/will/.stack/global-project/stack.yaml
# This is the implicit global project's config file, which is only used when
# 'stack' is run outside of a real project.  Settings here do _not_ act as
# defaults for all projects.  To change stack's default settings, edit
# '/Users/will/.stack/config.yaml' instead.
#
# For more information about stack's configuration, see
# http://docs.haskellstack.org/en/stable/yaml_configuration/
#
packages: []
resolver: lts-12.2
extra-deps: base-compat-0.9.3

Tried again:

$ stack install git-mediate
Could not parse '/Users/will/.stack/global-project/stack.yaml':
Aeson exception:
Error in $['extra-deps']: failed to parse field 'extra-deps': expected [a], encountered String
See http://docs.haskellstack.org/en/stable/yaml_configuration/

[Peaker]

I uploaded a new version.
Can you try stack update && stack install git-mediate ?

[Peaker]

Oh and remove your ~/.stack/global-project/stack.yaml. That belongs in git-mediate's stack.yaml which now exists

[yairchu]

Am also on 10.13.5, and just tested this with a clean stack installation and after @Peaker's changes it works now. (stack install git-mediate-1.0.3 indeed doesn't work)

[willsheppard]

Thanks.

I also found that running "stack install" from the git checkout directory worked before, as a workaround.