This removes the need to install any specific version of Python or
figure out how to configure it by instead asking users to install `uv`
and letting it manage Python. Among other advantages, `uv` is designed
to be fast enough to embed directly into our scripts.
We were already using this in `bench_runner.py` so that the script could
import non standard library dependencies. Moving to it for the rest of
our Python unifies the approach and will also enable dependencies
whenever needed.
I've left `github_tools` alone as it has special handling with its own
Bazel setup.
I've updated the contributing tools to explain the approach here.
The labeling script will now directly set a check status for the PR as
`pending` when it marks something as dependent, and clear it when it no
longer is. This emulates a check that starts when marked as dependent
and runs until the last dependency lands, allowing automerge and other
workflows to work cleanly.
The branch protection rule will have to be updated to the new spelling.
This should do the same key thing as #7113, but integrated to the new
script.
Assisted-by: Antigravity with Gemini
This should detect when a PR has a dependency of another open PR and add
a comment and label describing it. The comment will even do a
best-effort to compute the best starting commit for review.
Whenever PRs are closed, it will also scan the open depnedent PRs and
try to either remove the PRs in the comment or if it reaches zero the
label.
It works to update a single comment on a PR rather than adding more
comments.
Assisted-by: Antigravity with Gemini