Pre-commit: Issues with running under another virtualenv + fish shell and a workaround

[ustun]

I am using fish shell + project virtualenv.

Whenever I activate my project's virtualenv, running pre-commit would fail, with strange errors like `basename: command not found'.

sh /Users/ustun/.pre-commit/repoUMoyOJ/py_env-default/bin/activate: line 61: basename: command not found bash: xargs: command not found

However, after deactivating the virtualenv, pre-commit would run properly.

It turns out one of the reasons is the usage of bash -c.

fish sets path as space delimited values: /usr/bin /usr/local/bin as opposed to /usr/bin:/usr/local/bin.

When we run bash -c 'echo $PATH' for example, it still receives the $PATH of fish, not $bash.

I went ahead and replaced in my local pre-commit scripts everything that refers to bash with fish, and changes &&'s to ;

This fixed it for me. Just documenting in case it helps another person.

I'm still not sure why deactivating the project virtualenv helped, I guess there's some incompatibility by running activate.fish (fish specific script for venv) and then activate (bash specific script for venv).

I also tried bash -l -c to get a clean bash environment, but that didn't help.

[ustun]

Upon further inspection, it is the deactivate nondestructive line under activate that activates a bogus fish specific path inside bash shell.

  if ! [ -z "${_OLD_VIRTUAL_PATH+_}" ] ; then
        PATH="$_OLD_VIRTUAL_PATH"
        export PATH
        unset _OLD_VIRTUAL_PATH
    fi

Before this runs, $PATH is colon separated
When deactivate runs, $OLD_VIRTUAL_PATH is space delimited here, so $PATH will now be space delimited within bash.

Removing the deactivate line fixes the problem.

[asottile]

Fortunately, I'm currently factoring out bash and activate scripts entirely in my latest pull request so this should just magically fix itself!

[asottile]

I believe this is fixed via #355

@ustun can you try the latest version pip install git+git://github.com/pre-commit/pre-commit and see if it fixes this issue for you?

[asottile]

Can confirm fixed:

asottile@work /t/foo> source venv/bin/activate.fish 
(venv) asottile@work /t/foo> pip install pre-commit==0.7.6
...
Installing collected packages: pyyaml, aspy.yaml, virtualenv, functools32, jsonschema, cached-property, nodeenv, ordereddict, pre-commit
Successfully installed aspy.yaml-0.2.2 cached-property-1.3.0 functools32-3.2.3.post2 jsonschema-2.5.1 nodeenv-0.13.6 ordereddict-1.1 pre-commit-0.7.6 pyyaml-3.11 virtualenv-15.0.1
(venv) asottile@work /t/foo> pre-commit run --all-files
Check Yaml...............................................................Failed
hookid: check-yaml

/home/asottile/.pre-commit/repoMVYdJO/py_env-default/bin/activate: line 61: basename: command not found
bash: xargs: command not found

(venv) asottile@work /t/foo> pip install pre-commit==0.8.0
...
Successfully installed pre-commit-0.8.0 pyterminalsize-0.1.0
(venv) asottile@work /t/foo> pre-commit run --all-files
Check Yaml...............................................................Passed

[ustun]

Great, thank you very much!