Clarify expected working directory when tests are run about multibuild HOT 5 OPEN

Note this worked fine in appveyor.yml for Windows testing:

    - cd %REPO_DIR%\\Tests
    - "%CMD_IN_ENV% python run_tests.py --offline"

from multibuild.

Right - well - sort of - multibuild specifically changes into a temporary directory in order to run the tests, in order to make sure that the tests are running on the installed code not the source code.

This can get a bit ugly - for example, I had to copy lots of matplotlib files from the source to the installation directory in order to run the tests:

https://github.com/MacPython/matplotlib-wheels/blob/master/config.sh#L54

The problem is that, if you don't do this, it's difficult to know if you've properly tested what the user will get, when they install the wheel, but not the source.

from multibuild.

That looks like a very relevant example - thank you. I would ideally do much the same here, i.e. copy/link the test files into the temporary directory where there is no copy of the source code or build files present in a sister folder to confuse things.

So assuming we are in an arbitrary temporary directory, how best to determine the original source code folder? i.e. Can I assume ../project-name as used in MPL_SRC_DIR=../matplotlib here:

https://github.com/MacPython/matplotlib-wheels/blob/master/config.sh#L52

from multibuild.

Yes, you can assume that. The relevant set-up code is in a tiny function called install_run:

https://github.com/matthew-brett/multibuild/blob/master/common_utils.sh#L241

Like any other bash function, you can override that in your config.sh, if you like.

from multibuild.

Thank you. I still have some test oddities from the slightly different environment to resolve (unrelated to this particular issue) before exploring this...

from multibuild.