$ git clone -n https://src.fedoraproject.org/rpms/ghc-Only.git /var/lib/mock/f45-build-9931-411/root/chroot_tmpdir/scmroot/ghc-Only
Cloning into '/var/lib/mock/f45-build-9931-411/root/chroot_tmpdir/scmroot/ghc-Only'...
$ git fetch origin 01e73463f2a5f8a6beaff07b672f84ce4e88aeb9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-Only
 * [new ref]         01e73463f2a5f8a6beaff07b672f84ce4e88aeb9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 01e7346 Rebuilt for https://fedoraproject.org/wiki/Fedora_45_Mass_Rebuild