PYTHONPATH - let's systematically tame the baest

[Hartmut Goebel <h.goebel@crazy-compilers.com>]

Hi,

let's pick up on this issue and systematically design the test-cases to
benchmark the proposed solutions. I already prepared a test-script to
simplify this and will provide a full description as later.

**Please comment if any relevant case is missing or if any case can be
skipped**

1) Test-cases

For all environments (see below) these cases must give the expected
output - which is defined by what a "foreign distribution's" python
would do:
- "installed" python
- venv with and without --system-site-packages
- stacked venv with and without --system-site-packages

2) Environments to be tested.

The proposed solution must pass the test-suite in all of these environments:

2.1 guix environment:

     guix environment --ad-hoc python -- python3 testit
      --> Expected outcome: site-packages from GUIX_ENVIRONEMENT

2.2 guix environment with container:

     guix environment -C --ad-hoc python -- python3 testit
      --> Expected outcome: site-packages from GUIX_ENVIRONEMENT

2.3 Installed package *without setting the environment variables!*

     guix package -i python && ~/.guix-profile/bin/python3 testit
    --> Expected outcome: site-packages from ~/.guix-profile/
    --> Shall this work, too? Is it nice-to-have or useless?

2.4 running from /gnu/store (directly)

    $(readlink -f ~/.guix-profile/bin/python3) testit
    --> Expected outcome: site-packages from /gnu/store
    --> What is the expected outcome? What is the expected

2.5 running from /gnu/store (via link)

    ln -s $(readlink -f ~/.guix-profile/bin/python3)
/tmp/test-guix-pythonA.exe ;
    /tmp/test-guix-pythonA.exe testit
    --> Expected outcome: site-packages from /gnu/store

2.6 Installed in GuixSD

    --> Do we need to test this? Or is this already covered by one of
the other cases?

-- 
Regards
Hartmut Goebel

| Hartmut Goebel          | h.goebel@crazy-compilers.com               |
| www.crazy-compilers.com | compilers which you thought are impossible |