On Wed, Mar 27, 2024 at 03:11:08PM -0700, Junio C Hamano wrote:

This seems to fail only on Windows, and I have run out of my today's
allotment of time for this topic.

The earlier part that creates the directory with a trailing SP,
redirects to a file in such a directory to create an empty file, and
adds that path to the index, all succeed and follow the &&-chain,
but the step that runs "git diff" with "funny /" (i.e. the name of
the directory a trailing slash) as the pathspec produces an empty
patch, and "git apply" would of course choke on an empty file as an
input.

With the following band-aid, we can skip the test and the output
from "sh t4126-*.sh -i -v -x" might give us a clue that explains how
such a failure happens.  Unfortunately GitHub CI's win test does not
give us insight into a test that did not fail, so I did not get
anything useful from the "ls -l" down there (I already knew that
sample patches are empty files).

We package up the failed test output and trash directories for each run.
You can find the one for this case here:

  https://github.com/git/git/actions/runs/8458842054/artifacts/1364695605

It is sometimes misleading because we don't run with "-i", so subsequent
tests may stomp on things. But in this case the failing test is the last
one. Unfortunately, I don't think it shows us much, because the state we
tried to diff is removed by the test itself (both the funny dir and the
index after we tried to add it).

So I don't know if we failed to even create "funny /" in the first
place, if adding it to the index failed, or if the diff somehow failed.

On the plus side, while trying to find the failing CI job, I ran across
and diagnosed two other unrelated failures in "seen". ;)

-Peff