Re: [gentoo-python] RFC: Redesign for 'best implementation' in python-r1

[Michał Górny]

Dnia 2014-12-27, o godz. 14:50:43
Michał Górny <mgorny@g.o> napisał(a):

> 3. we introduce extra variable for distutils-r1 (oh cruel world, how
> should we name it?!) that applies wildcards to python_*_all() phases.

Ok, I see a problem with this one. Consider the common use:

  DEPEND="doc? ( dev-python/epydoc[$(python_gen_usedep 'python2*')] )"
  REQUIRED_USE="doc? ( $(python_gen_useflags 'python2*') )"

  python_compile_all() {
    use doc && esetup.py doc # runs epydoc
  }

So we'd like the _all() phase to be run with python2* because of epydoc.
But OTOH we don't need any python2* if USE=-doc.

If we used a simple variable to control impl for _all(), it would
unnecessarily force python2* with USE=-doc, and python2* may not be
enabled at all then. So we either set it conditionally (+ extra phase,
added complexity), or make it non-fatal. Non-fatal is ugly since it
means unpredictable behavior.

So we can use a complex variable instead. But this way, we're in
python.eclass territory soon. Alternatively, add some function that's
called random-early by other python stuff, and that can be used to set
this variable -- but this doesn't look like good API design.

Maybe calling python_setup inside _all() phases -- but this implies
setting at least two environments, and we'd have to handle extra stuff
that distutils-r1 sets like PYTHONPATH. Still doesn't sound good.

So any ideas? :P

-- 
Best regards,
Michał Górny