detected dubious ownership in repository

[jleibs]

There is a pathological set of conditions that can result in:

Failed to run 'git ["rev-parse", "HEAD"]':

  fatal: detected dubious ownership in repository at '/__w/rerun/rerun'
  To add an exception for this directory, call:

  	git config --global --add safe.directory /__w/rerun/rerun

This is discussed at length in this thread:
actions/runner-images#6775 (comment)

We worked around it by adding:

RUN git config --system --add safe.directory *

to the docker image as advised.

However, when the docker image accidentally migrated from git 2.25.1 to 2.30.2 the above fix appears to have stopped working.

I tried changing the behavior to:

git config --global --add safe.directory '/__w/rerun/rerun'

however when building the image I ended up back on git 2.25.1 and that fails as well.
Related to:

• Incremental docker ci_builds are invalidating more layers than they should #1188

At present the only known combination of functioning behavior is:

git version 2.25.1

RUN git config --system --add safe.directory *

It's likely the case that until we figure out a deterministic way of building a docker container that works that @jleibs needs to be the one to publish updates to our docker container for the time being.