通过Tox命令设置$ PATH

Question

Currently using tox to test a python package, and using a python library ( chromedriver-binary ) to install chromedriver .

This library creates a script ( chromedriver-path ) which when called outputs the PATH where chromedriver is installed. The usual way to use this is to run:

export PATH=$PATH:`chromedriver-path`

I've tried the following without success in tox.ini

setenv= 
  PATH = {env:PATH}{:}`chromedriver-path`

This errors as expected:

FileNotFoundError: [Errno 2] No such file or directory: 'chromedriver': 'chromedriver'

Implying that the setenv command is never called/run.

commands=
  export PATH=$PATH:`chromedriver-path

This fails with:

ERROR: InvocationError for command could not find executable export

How do I make this work?

Answer 1

Commands can't change their parent processes' environment variables, and thus can't change the environment variables of subsequent commands launched by forking that parent; they can only set environment variables for themselves or their own children.

If you were able to collect the output of chromedriver-path before starting tox , this would be moot. If it's only available in an environment tox itself creates, then things get a bit more interesting.

One approach you can follow is to wrap the commands that need this path entry in a shim that adds it. Consider changing:

commands=
  py test ...

to:

commands=
  sh -c 'PATH=$PATH:$(chromedrive-path); exec "$@"' _ py test ...