The Gazelle Python Manifest hash: how critical is it? Can we add a flag to remove it?

[dougthor42]

AIUI, the gazelle python manifest hash line only exists so that gazelle_python_manifest.test can return quickly.

What are the thoughts on optionally removing the hash? Eg via something like:

gazelle_python_manifest(
    name = "gazelle_python_manifest",
    modules_mapping = ":modules_map",
    experimental_exclude_hash = True,  # bleh. Maybe experimental_include_hash = False (default True) is more readable
)

Context:

Our CI pipeline recently slowed down significantly because we moved to an internal python package index that is having some latency issues. This means that when people run gazelle_python_manifest.update, it can take on the order of minutes. It also means that our entire CI pipeline takes upwards of 30 minutes.

Some days we have a lot of changes to our python dependency versions, and thus a lot of changes to the gazelle_python.yaml hash. This means that users get CI conflicts on the hash and have to rebase and restart the process again, only to have some other change swoop in and cause a different conflict on the hash. It can be frustrating.

Of course, this isn't an issue with rules_python, but adding an option that removes the hash would resolve (readL hide/mask) at least some problems.

Our CI is set up to run gazelle_python_manifest.test as one of the first steps. I assume that removing the hash would mean that this step now takes O(minutes), but on the user side they would not have to deal with merge conflicts, saving them O(hours).