$ git clone -n https://src.fedoraproject.org/rpms/fbgemm.git /var/lib/mock/f45-build-52013-905/root/chroot_tmpdir/scmroot/fbgemm
Cloning into '/var/lib/mock/f45-build-52013-905/root/chroot_tmpdir/scmroot/fbgemm'...
$ git fetch origin 9e7cf40432b5e666d5fc813485c34cddc95e023a:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/fbgemm
 * [new ref]         9e7cf40432b5e666d5fc813485c34cddc95e023a -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 9e7cf40 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild