$ git clone -n https://src.fedoraproject.org/rpms/gt.git /var/lib/mock/f45-build-13138-446/root/chroot_tmpdir/scmroot/gt
Cloning into '/var/lib/mock/f45-build-13138-446/root/chroot_tmpdir/scmroot/gt'...
$ git fetch origin 8939cff5f97c83c11e347dc83e6e9d4f674a294b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gt
 * [new ref]         8939cff5f97c83c11e347dc83e6e9d4f674a294b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8939cff Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild