$ git clone -n https://src.fedoraproject.org/rpms/ctstream.git /var/lib/mock/f45-build-5474-339/root/chroot_tmpdir/scmroot/ctstream
Cloning into '/var/lib/mock/f45-build-5474-339/root/chroot_tmpdir/scmroot/ctstream'...
$ git fetch origin b2f3e3ea0c7c1d6474942553e6f00fd7b12330c5:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ctstream
 * [new ref]         b2f3e3ea0c7c1d6474942553e6f00fd7b12330c5 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b2f3e3e Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild