$ git clone -n https://src.fedoraproject.org/rpms/rubygem-gtk2.git /var/lib/mock/f40-build-777923-129637/root/chroot_tmpdir/scmroot/rubygem-gtk2
Cloning into '/var/lib/mock/f40-build-777923-129637/root/chroot_tmpdir/scmroot/rubygem-gtk2'...
$ git fetch origin 28d2af65f6f240586867ddd148fca44585e24d12:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rubygem-gtk2
 * [new ref]         28d2af65f6f240586867ddd148fca44585e24d12 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 28d2af6 Rebuilt for https://fedoraproject.org/wiki/Fedora_40_Mass_Rebuild