1. Relying on `python3 -m pytest --help` to test for pytest can fail
because the pytest packages's __main__ is still invoked; this can
trigger import problems and falsely indicate that pytest is missing.
A simpler test is to just confirm that pytest is importable. If so,
the interpreter returns 0. Otherwise, an ImportError is thrown and
the interpreter will return 1.
2. Many templates require a custom do_check just to set PYTHONPATH to
either a build directory (especially for compiled extensions) or some
subdirectory of the source tree. Setting PYTHONPATH automatically to
the build directory should drastically reduce the need for custom
do_check in py3 templates. (This only applies to python3-module.sh
because pep517 builders will have unpredictable build directories.)
Closes: #31354.
There is no need to use a custom build directory for python{2,3}-only
modules.
This indirectly fixes our issues with packages that use distutils-extra.
in order to make gufw installation process work, it includes itself
while installing. this raise the need that the build directory needs
to be a valid python identifier too. this commit solves this issue.
- python_module build style now builds modules for python2/3 by default
- new python2_module and python3_module build styles for building
python2-only and python3-only packages respectively
- no more python_versions
- no need to define pycompile_version for Python modules anymore
(still needed for non-Python modules though)
- Python version and paths are now guessed automatically and a set of
useful variables can now be used in templates
- #!/usr/bin/python2 and #!/usr/bin/python3 are now the default shebangs
- /usr/bin/foo2 and /usr/bin/foo3 are now the default names for bin
scripts (for use with alternatives)
