Why is my Ruby Git script hook run with the wrong $PATH?

Question

I'm using RVM. I wrote a Git pre-commit hook for a project:

#!/usr/bin/env ruby

puts RUBY_VERSION
puts `echo $PATH`
exit(1)

which outputs this when run by Git:

$ git ci -m 'foo'
1.8.7
/usr/libexec/git-core:/usr/bin:/usr/local/heroku/bin:/Users/mgoerlich/.rvm/gems/ruby-2.0.0-p195@global/bin:/Users/mgoerlich/.rvm/rubies/ruby-2.0.0-p195/bin:/Users/mgoerlich/.rvm/bin:/Users/mgoerlich/adt-bundle-mac-x86_64-20130219/sdk/platform-tools:/Users/mgoerlich/adt-bundle-mac-x86_64-20130219/sdk/tools:/usr/local/bin:/usr/local/sbin:/Users/mgoerlich/.dotfiles/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/bin/core_perl:/Users/mgoerlich/bin:/usr/local/share/npm/bin:/usr/local/share/npm/bin

It seems to run with the wrong version of Ruby because $PATH is not the same as in bash or zsh or sh. It seems like git is manipulating $PATH. When run manually, I get this:

$ .git/hooks/pre-commit
2.0.0
/usr/local/heroku/bin:/Users/mgoerlich/.rvm/gems/ruby-2.0.0-p195@global/bin:/Users/mgoerlich/.rvm/rubies/ruby-2.0.0-p195/bin:/Users/mgoerlich/.rvm/bin:/Users/mgoerlich/adt-bundle-mac-x86_64-20130219/sdk/platform-tools:/Users/mgoerlich/adt-bundle-mac-x86_64-20130219/sdk/tools:/usr/local/bin:/usr/local/sbin:/Users/mgoerlich/.dotfiles/bin:/usr/bin:/bin:/usr/sbin:/sbin:/usr/bin/core_perl:/Users/mgoerlich/bin:/usr/local/share/npm/bin:/usr/local/share/npm/bin

In the output of the commit hook, there are two paths prepended, one of them /usr/bin where the system Ruby's executable is placed.

Is this a known behavior? Can I manipulate that somehow? I know I could specify the full path to the correct Ruby version in the shebang, but this is not what I want.

Answer 1

The reason i didn't wanted to use env instead of a fixed path to ruby or a rvm wrapper was that this is for a Team Project and not everyone in the Team is using RVM.

My final solution was to write my own wrapper script an add it to that project.

All client-side git hooks 're living in $PROJECT/bin/hooks, all of them ruby scripts. Now, i've just put that mentioned wrapper in there, and created a symlink to that wrapper in $PROJECT/.git/hooks for all the hooks.

The script check's if RVM is used and if so fixes the $PATH var and if there are .ruby-version and/or .ruby-gemset files in the project root it loads the according version/gemset.

Then it'll run the according ruby script Here's the wrapper in case you're interested:

#!/bin/bash
if [ -d "$HOME/.rvm/bin" ]; then
  PATH="$HOME/.rvm/bin:$PATH"
  [[ -s "$HOME/.rvm/scripts/rvm" ]] && source "$HOME/.rvm/scripts/rvm"

  if [ -f ".ruby-version" ]; then
    rvm use "$(cat .ruby-version)"
  fi

  if [ -f ".ruby-gemset" ]; then
    rvm gemset use "$(cat .ruby-gemset)"
  fi
fi
ruby "bin/hooks/$(basename "$0").rb"

So, i'll get my rvm version/gemset and everybody else the ruby version they have in their PATH, and everyone is Happy.

Answer 2

you need to set ruby to a wrapper:

#!$rvm_path/wrappers/ruby-2.0.0-p195/ruby

You can simplify it with an alias:

rvm alias create git_hooks 2.0.0-p195

And then the ne shebang will look like this:

#!$rvm_path/wrappers/git_hooks/ruby

In the file just make sure to replace $rvm_path with /Users/mgoerlich/.rvm so finally it looks like:

#!/Users/mgoerlich/.rvm/wrappers/git_hooks/ruby

Answer 3

What I ended up doing is: the .git file structure:

• .git/hooks/pre-commit
• .git/hooks/pre-commit-main.rb

.git/hooks/pre-commit:

#!/usr/bin/env bash
export PATH="$THE_GOOD_PATH"
ruby "$GIT_DIR/hooks/pre-commit-main.rb"

.git/hooks/pre-commit-main.rb:

#!/usr/bin/env ruby
puts RUBY_VERSION

Then, when you call git commit, make sure that THE_GOOD_PATH, is defined:

export THE_GOOD_PATH="$PATH"
git commit

You could also export THE_GOOD_PATH="$PATH" from your .profile or the toplevel of your application and symlink all hooks to a single file.

This method has the advantage of being rbenv agnostic: it also works with RVM or Python virtualenv.

I wrote to the Git developers at: http://permalink.gmane.org/gmane.comp.version-control.git/258454 asking them to leave our PATH alone, but the initial reply was WONTFIX.