tests: Revert to using --owner-uid=$(id -u)

[cgwalters]

This allows the test suite to run as non-root again. When operating
on a bare non-root repo, we can't chown().

(Arguably, non-root bare repos are not very useful and we shouldn't
test them or potentially even support them, but that's a whole
other thing)

[lucab]

As a non-root make check, locally for me this is a PASS either with or without of this patch. I'm thus unsure about the real backstory, but your explanation makes sense.
Perhaps we can directly avoid all issues by using a less intrusive flag which still enables the commit modifier, like --mode-ro-executables.

[cgwalters]

As a non-root make check, locally for me this is a PASS either with or without of this patch.

I don't understand how that's possible. What is your build environment/setup, specifically? For me it's running in toolbox.

[lucab]

Nothing fancy, a Debian 11/stable workstation and a boring interactive user.
But it seems to also be fine in a bare debian:stable container and a fresh unprivileged user:

[core@coreos-scratch ~]$ podman run --rm -ti debian:stable
[... installing libs/git/automake ...]
root@6bf8b85b3c03:/# useradd -m devuser
root@6bf8b85b3c03:/# su - devuser
devuser@6bf8b85b3c03:~$ id       
uid=1000(devuser) gid=1000(devuser) groups=1000(devuser)
devuser@6bf8b85b3c03:~$ pwd
/home/devuser
devuser@6bf8b85b3c03:~$ git clone --depth 1 https://github.com/ostreedev/ostree.git && cd ostree && ./autogen.sh && make -j && make check
[...]
PASS: tests/test-basic-user.sh 36 commit from ref with modifier
[...]
PASS: tests/test-basic-user-only.sh 36 commit from ref with modifier
[...]
============================================================================
Testsuite summary for libostree 2021.4
============================================================================
# TOTAL: 875
# PASS:  832
# SKIP:  43
# XFAIL: 0
# FAIL:  0
# XPASS: 0
# ERROR: 0
============================================================================

[cgwalters]

It's test-basic.sh failing for me. In this case we represent uids just as they are on disk, so it cannot work to do --owner-uid=0 as non-root by default.

But clearly, something apparently did work in #2424 and I believe you it works locally.

One thing I'm narrowing in on is that I am passing through /var/tmp from the host so I get xattr support.

[cgwalters]

One thing I'm narrowing in on is that I am passing through /var/tmp from the host so I get xattr support.

Yup from the CI logs:
SKIP: tests/test-basic.sh - this test requires xattr support

[cgwalters]

OK there's more here to do; marking draft.

[cgwalters]

OK yeah. A lot of history here.
654b0c4
for example.