Re: AIX failures on parallel checkout (new in v2.32.0-rc*)

Matheus Tavares Bernardino [off-list ref] writes:

Hi, Ævar

On Wed, May 26, 2021 at 3:40 PM Ævar Arnfjörð Bjarmason
[off-list ref] wrote:

quoted

    + test_checkout_workers 0 git -C various_sequential checkout --recurse-submodules B2
    error: Your local changes to the following files would be overwritten by checkout:
            d
            h
            j
    Please commit your changes or stash them before you switch branches.
    Aborting

I requested an account on the GCC farm to debug this, and the problem
seems to be that AIX's `cp -R` defaults to following symlinks instead
of copying them. In the above error message, 'd', 'h' and 'j' are all
symlinks which were followed when copying the test repo, so these
paths indeed won't match what's in the index, which makes checkout
abort.

Fortunately, there is a POSIX option to force cp to copy the symlinks:
'-P'. Adding this flag to the cp invocation at line 117 of t2080 makes
all parallel checkout tests pass on AIX.

We also already use `cp -R -P` in the test suite (at t7001), and
without any prereq, so I guess all platforms we are testing git at do
support this flag in cp. I'll send a patch adding the flag at t2080.

Thanks for a quick analysis.  Very much appreciated.

00764ca1 (test: fix t7001 cp to use POSIX options, 2014-04-11) only
mentions that "-R -P -p" is used now in place of "-a" that we used
to use (the latter of which is not POSIX).  Please highlight why we
want -P in the log message (i.e. we want to copy the link in these
tests because ...) for the fixing commit.

Thanks.