$ git clone -n https://src.fedoraproject.org/rpms/bird.git /var/lib/mock/f38-build-side-42-init-devel-913139-28703/root/chroot_tmpdir/scmroot/bird
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-913139-28703/root/chroot_tmpdir/scmroot/bird'...
$ git fetch origin 19a98322754dba581384710a17a5fef036226085:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/bird
 * [new ref]         19a98322754dba581384710a17a5fef036226085 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 19a9832 Upgrade to 2.13.1 (#2190169)