07:08 <Joannah> 10:00

07:08 <Joannah> Hi mattip , Carl recommended I contact you. What is the story with numpy/scipy/scikit-learn and PyPy? Am trying to pip install them using the ./pypy-3.9-c but they fail. Is there something am missing, like pypy doesnt support them?

07:14 <mattip> hi. You need to compile them, since pypy-3.9 is very new. But the compilation should JustWork on linux. What platform are you on?

07:15 <mattip> conda is intending to start a migration for pypy3.8 and pypy3.9 soon, which means you theoretically could use conda to get binary packages,

07:15 <mattip> but it will take a while to get it all going

07:16 <Joannah> Am on debian

07:40 <mattip> weird. We regularly build numpy with HEAD, so that should work

07:44 <mattip> I recently built scipy too. I haven't tried scikit-learn. pypy3.7 has all of them on conda

07:45 <mattip> conda create -n pypy_test_env pypy3.7; conda activate pypy_test; conda install scikit-learn

07:46 <mattip> joannah (for the logs): can you put the traceback on a pastebin somewhere?

07:55 <ctismer> Hi mattip! I observed that objects are not immediately collected after `gc.collect()`. I have to call it twice. Why? Can I avoid this?

07:56 <mattip> sometimes you have to call three times, it is to untangle reference loops

07:58 <ctismer> Thank you, I hoped for that answer. Then I can calm down my colleagues 😉

08:03 <mattip> I am pretty sure this is true on CPython as well

08:09 <ctismer> Yes, but normally we see immediate deletion. And I did not know how the PyPy GC differs.

08:09 <ctismer> So we needed to change many tests.

08:10 <LarstiQ> also the "normally" is not guaranteed on CPython

08:11 <mattip> it is much healthier in general to separate obj.close() from obj.__del__(), and use some kind of context management to call obj.close()

08:12 <mattip> rather than depending on refcount semantics to "automatically" call obj.__del__() -> obj.close()

08:21 <mattip> It seems we have a new advocate for PyPy in Anthony Shaw

08:21 <mattip> https://tonybaloney.github.io/posts/pypy-in-production.html

08:25 <mattip> https://nitter.net/anthonypjshaw/status/1501106422402396171

08:29 <ctismer> LarstiQ: Yes, I was talking about our test cases which check object deletion and things work without cycles, where PyPy needs two GC calls. I was wondering about the second.

09:15 <cfbolz> Snow snow!

09:38 <LarstiQ> cfbolz: ah, had it disappeared?

09:39 <cfbolz> We didn't really have much this winter

09:39 <cfbolz> But now I am hiking for two days, and finding lots here in Hessen in the forest

09:39 <LarstiQ> cool :)

09:40 <LarstiQ> we've had heaps more than in recent years, lots of skiing and skating in daycare.