$ git clone -n https://src.fedoraproject.org/rpms/mathjax.git /var/lib/mock/f39-build-1560052-37330/root/chroot_tmpdir/scmroot/mathjax
Cloning into '/var/lib/mock/f39-build-1560052-37330/root/chroot_tmpdir/scmroot/mathjax'...
$ git fetch origin b059a6a694ee46141cc100f9513b8a3680fd71e8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mathjax
 * [new ref]         b059a6a694ee46141cc100f9513b8a3680fd71e8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b059a6a Rebuilt for https://fedoraproject.org/wiki/Fedora_39_Mass_Rebuild