[gentoo-dev] [RFC] Dropping PyPy(3) back to ~arch

[Michał Górny]

Hi,

I think I've made a mistake by stabilizing PyPy(3), and I would like to
drop it back to ~arch (and stable-mask the relevant flags).

Roughly, there are 4 problems with it:

1. The current stable (both Gentoo and upstream) is PyPy3.6 that is
equivalent to CPython 3.6.  Yes, the one we removed already.  People
using this version are already hitting issues because of upstreams
dropping py3.6 support or us failing to provide proper compatibility.

2. The next branch, PyPy3.7 is still in alpha state upstream.  It has
a few major bugs, e.g. the regex engine is sometimes slightly broken. 
The stdlib tests are mostly broken (compared to moderately broken
in 3.6).

3. To the best of my knowledge, there's no work hapenning to have
PyPy3.8, so it will keep being behind CPython.

4. PyPy upstream doesn't merge CPython stdlib changes timely, nor takes
care of vulnerabilities inherited from CPython.

5. PyPy3 doesn't give the same ABI stability guarantees as CPython,
and our choice not to slot between PyPy3 versions doesn't help (and it's
not worth changing considering all the other points).  Upgrading PyPy3
involves intermittent breakage, and people using it with Portage (which
is my fault) experience fatal breakage.


Honestly, I've tried to improve PyPy in the past but I don't really have
time or motivation to do this continuously.  PyPy is an interesting
project, and it has its isolated uses.  However, I don't think it's
ready as a general-purpose Python interpreter for production
environments.

I don't really want to remove it entirely or revert all the work we've
put into testing packages with it -- but I think we should move it to
~arch at the very least.

WDYT?

-- 
Best regards,
Michał Górny