$ git clone -n https://src.fedoraproject.org/rpms/gbdfed.git /var/lib/mock/f45-build-9639-407/root/chroot_tmpdir/scmroot/gbdfed
Cloning into '/var/lib/mock/f45-build-9639-407/root/chroot_tmpdir/scmroot/gbdfed'...
$ git fetch origin 8d6d0706669c2a23c2885aa67c10a68422bcc8d8:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/gbdfed
 * [new ref]         8d6d0706669c2a23c2885aa67c10a68422bcc8d8 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 8d6d070 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild