Speed up pypy builder, which is slow due to coverage.py

[itamarst]

Options:

• Newer versions of coverage.py (post-6.4.1) apparently run a lot faster on PyPy. In practice, didn't help (see below).
• Drop coverage usage on PyPy.
• Just live with it and close this issue.

[itamarst]

coverage.py 7.3.3 seems to take infinite amounts of time on PyPy for me, even slower than current CI using 4.3.1. Will try other versions.

[itamarst]

Pretty much every version I've tried is ludicrously slow on my computer, weirdly much slower than CI, so it's difficult for me to see if upgrading helps...

Another alternative is to skip collecting coverage on PyPy, which will speed it up a lot!

[4383]

I'm currently doing some tests with different coverage versions, will post my observations here

[4383]

With version 7.3.3:

$ time tox
...
real    2m50.077s
user    1m29.733s
sys     0m6.130s

With current version (4.5.1):

$ time tox
...
real    3m4.032s
user    1m41.401s
sys     0m7.172s

On my local machine 7.3.3 is a bit faster.

[jstasiak]

Another alternative is to skip collecting coverage on PyPy, which will speed it up a lot!

If it's slow enough to be an impediment then this feels like a reasonable solution.

[itamarst]

I'm currently doing some tests with different coverage versions, will post my observations here

Your numbers are quite different than mine, mine just runs for 10+ minutes before I just give up and kill it. No idea what's different :(

[itamarst]

As reference in CI it currently takes 10 minutes, vs 2 minutes for everything else. Given @4383's numbers it seems like upgrading to 7.3.3 should help, but maybe not enough.

[itamarst]

Regardless, I probably need this for #638 so will upgrade in the branch for that.

[itamarst]

#836 upgrades to 7.3.3 and there's no meaningful impact on runtime. There's only one tiny bit of code that checks for PyPy, and I bet it could just be made unconditional, in which case coverage on pypy can be dropped.

[4383]

I agree with that