On Thu, 2020-03-26 at 14:13 -0500, William Hubbs wrote: > There are situations in which downstream overlays need to have versions > of python which Gentoo no longer supports in the tree. > > Currently, the only way to do this is for the overlay author to fork > python-utils-r1.eclass. This is highly undesirable since it creates a > very significant maintenance burden for the overlay author. > > There are a couple of things we can do upstream to make this easier, and > I think we should do one of them. > > The simplest way would be to apply the following patch. > In this situation, all the overlay author > would have to do is adjust the PYTHON_COMPAT_ALLOW_EXTRA_IMPLS variable. > > The other option would be to move _PYTHON_ALL_IMPLS and the > implementation of _python_impl_supported to a separate eclass, e.g. > python-impls-r1.eclass. This eclass could be forked freely downstream > without worrying about the other python eclasses. > I will volunteer to do the legwork for this option if we do not like the > first one. > > I would advocate the first option however since no one has to fork > anything. > > Thoughts? > > William > > William Hubbs (1): > python.eclass: add PYTHON_COMPAT_ALLOW_EXTRA_IMPLS > > eclass/python-utils-r1.eclass | 2 ++ > 1 file changed, 2 insertions(+) >
How do you prevent some extra clever Gentoo developer from doing the following in ::gentoo dev-python/foo/foo-1.ebuild: # don't have the time to port this right now, patches welcome PYTHON_COMPAT_ALLOW_EXTRA_IMPLS=( python3_4 ) PYTHON_COMPAT=( python3_4 ) inherit distutils-r1 Furthermore, defining PYTHON_COMPAT_ALLOW_EXTRA_IMPLS is going to break metadata invariance, causing tons of cache mis-hits. How do you prevent that? In addition, this will very quickly cause whatever overlay this is being used in to become invalid. Imagine I have dev-python/foo::gentoo that supports python 3.4 and 3.5 and have dev-python/bar::sony supporting 3.4 and 3.5 sitting in a hypothetical overlay, which depends on dev-python/foo::gentoo. Now we remove python 3.4 from ::gentoo in python-utils-r1, and one week later we remove python3.4 from dev-python/foo::gentoo's PYTHON_COMPAT. Now your dev- python/bar::sony in conjunction with PYTHON_COMPAT_ALLOW_EXTRA_IMPLS has an invalid depgraph. How do you wish to resolve this? I feel like keeping up with ::gentoo is ultimately the better strategy than trying to add backdoors to eclasses because some overlays are somewhat behind. Regards David
