[CI][Python] AMD64 Conda Python 3.10 Pandas 1.3.4 job consistently timing out

[adamreeve]

Describe the bug, including details regarding any error messages, version, and platform.

Eg. see https://github.com/apache/arrow/actions/runs/26083383511/job/76690298383

This appears to be hanging at mamba install -q -y --file arrow/ci/conda_env_sphinx.txt && pip install linuxdoc && mamba clean --all --yes

This times out after an hour, but on similar jobs, this only takes 30 seconds: https://github.com/apache/arrow/actions/runs/26083383511/job/76690298131#step:6:313

Component(s)

Continuous Integration, Python

[adamreeve]

Running this locally (PYTHON=3.10 PANDAS=1.3.4 NUMPY=1.21.2 archery docker run conda-python-pandas) and removing the -q argument to mamba install, it looks like mamba is taking a very long time to resolve packages:

STEP 5/10: RUN mamba install -y --file arrow/ci/conda_env_sphinx.txt
Fetch Shard Index for conda-forge/linux-64                                                      ⧖ Starting
Fetch Shard Index for conda-forge/linux-64                                                ✔ Done (0.1 sec)
Fetch Shard Index for conda-forge/noarch                                                        ⧖ Starting
Fetch Shard Index for conda-forge/noarch                                                  ✔ Done (0.1 sec)
Fetching and Parsing Packages' Shards                                                           ⧖ Starting
Fetching and Parsing Packages' Shards                                                     ✔ Done (8.0 sec)
Using Cached Shard Index for conda-forge/linux-64                                                   ✔ Done
Using Cached Shard Index for conda-forge/noarch                                                     ✔ Done
Fetching and Parsing Packages' Shards                                                           ⧖ Starting
Fetching and Parsing Packages' Shards                                                     ✔ Done (0.7 sec)

Pinned packages:

  - python=3.10

Resolving Environment                                                                           ⧖ Starting

It has been running for a while and is using 100% of 1 CPU core, I'll wait and see if it ever finishes. (edit: Killed this after 5.5 hours)

[adamreeve]

It looks like pinning versions of some dependencies might help speed up the mamba solver: mamba-org/mamba#3970 and pandas-dev/pandas#61594

[adamreeve]

Looks like this might be due to this recent regression in mamba, see mamba-org/mamba#4274. This mentions that the problem seems specific to Python <= 3.10.

I tested pinning to an older version of miniforge which seemed to fix the issue although I hit a different problem that I think is specific to my dev machine. I'll make a PR with this.

[raulcd]

Issue resolved by pull request 49999
#49999