[gentoo-python] pycrypto / pycryptodome business

[Michał Górny]

Hi,

So here's a quick summary of what I've established so far about
pycrypto/pycryptodome.

pycrypto is abandoned and dead since 2013. It was forked into
pycryptodome which is now maintained. The fork is partially compatible
with pycrypto -- though some APIs were removed/replaced. From my quick
experiments, every second random package I tried worked ;-).

Now, pycryptodome has two modes of install. When it's installed as
'pycryptodome' it installs 'Crypto' Python package -- which is the same
name as pycrypto used, and is therefore more compatible with packages
using the latter. There is also the alternative 'pycryptodomex' mode
which uses 'CryptoDome' namespace and does not collide with pycrypto.

For an initial attempt, I've added dev-python/pycryptodome using
the former mode since it was required by a revdep. But it also means
that it blocks pycrypto, and therefore we need to start looking into
adding compatibility with pycryptodome into more packages.

The problem is, as usual, setuptools/pkg_resources magic. Because even
if a particular app uses APIs that are compatible between the two
packages, pkg_resources will reject to run an app that specifies
'pycrypto' as a dependency if pycryptodome is installed, and the other
way around. From a quick look at the specification, those dependency
specs don't really support any kind of any-of.

That is, I think it is reasonable to assume that the only way forward
upstream would be to replace the dependency with 'pycryptodome',
and start requiring the latter.

As for Gentoo, I think the sanest way forward would be to live with
that. Start testing packages with pycryptodome. If they don't use
pkg_resources and API compatibility can be achieved, add || (
pycryptodome[...] pycrypto[...] ) if supported. If that is not possible,
a revbump switching to pycryptodome would be reasonable.

After all, we don't really have many revdeps [1] to port.

Any other ideas?

[1]:https://qa-reports.gentoo.org/output/genrdeps/rindex/dev-python/pycrypto

-- 
Best regards,
Michał Górny