uv hangs on install

[hauntsaninja]

uv hangs on various installs for me. The hangs are weirdly deterministic, except for when I really want them to be deterministic and then they stop being so. Anyway, I've got it down to something small that repros reasonably often. The full unminimised case with like 1000 packages always hangs.

In the official Python 3.11 docker image, with uv --version equal to uv 0.1.16, run the following:

import subprocess
from collections import Counter
def run(cmd):
    try:
        subprocess.check_call(cmd, shell=True, timeout=10)
    except Exception as e:
        return type(e)
    return None
Counter(run("uv cache clean; rm -rf .venv; uv venv; uv pip install --no-cache-dir --no-deps --compile ddtrace==2.6.2 debugpy==1.8.1 decorator==5.1.1 defusedxml==0.7.1 ecdsa==0.18.0 ecos==2.0.13 editorconfig==0.12.4 einops==0.7.0") for _ in range(10))

You'll see something like Counter({subprocess.TimeoutExpired: 6, None: 3, subprocess.CalledProcessError: 1}) (and larger cases fail more reliably). The singleton crash is a spurious bytecode compilation failure, e.g.:

error: Failed to bytecode compile /root/tmpv/.venv/lib/python3.11/site-packages
  Caused by: Bytecode compilation failed, expected "/root/tmpv/.venv/lib/python3.11/site-packages/defusedxml/cElementTree.py", received: ""

You can't really reduce the set of packages further without the hangs going away, although you can get rid of --compile if you want

Anyway, uv making much more progress on installing big work environment from scratch than last time I tried :-)

[konstin]

The bytecode compilation failures look like #2245/#2278, but those should have been included in 0.1.16.

[hauntsaninja]

Hm, that output was from a less reproducible environment, it's possible I messed up the uv version (I had a few requirements files that contained uv so probably clobbered myself). I'd seen it a few times and so wanted to include it in the issue.

I haven't seen the bytecode crash in my careful docker repro, which is definitely uv 0.1.16. I'll remove the part about bytecode from the title and let you know if I see it again — thanks for fixing!

[charliermarsh]

I think I'm able to reproduce this.

[charliermarsh]

I was able to reduce it to ddtrace==2.6.2 debugpy==1.8.1 ecdsa==0.18.0 editorconfig==0.12.4.

[charliermarsh]

Don't worry, I added a bunch of debug logging and it stopped hanging 😂

[hauntsaninja]

Yeah, RUST_LOG=trace was a fix for me as well :D

[charliermarsh]

I've identified the problem. I think it's specific to --no-deps...

[charliermarsh]

Actually, to be more specific, I could see it manifesting without --no-deps, but --no-deps would make it way more likely.

[charliermarsh]

Fixed in the next release, thank you!

[hauntsaninja]

Nice, thanks for solving it!