$ git clone -n https://src.fedoraproject.org/rpms/fedora-gnat-project-common.git /var/lib/mock/f45-build-8855-396/root/chroot_tmpdir/scmroot/fedora-gnat-project-common
Cloning into '/var/lib/mock/f45-build-8855-396/root/chroot_tmpdir/scmroot/fedora-gnat-project-common'...
$ git fetch origin 157743b7ddeb85a57c1db485f2f5cd1076b9bad3:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fedora-gnat-project-common
 * [new ref]         157743b7ddeb85a57c1db485f2f5cd1076b9bad3 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 157743b Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild