$ git clone -n https://src.fedoraproject.org/rpms/ghc-half.git /var/lib/mock/f40-build-1997942-44192/root/chroot_tmpdir/scmroot/ghc-half
Cloning into '/var/lib/mock/f40-build-1997942-44192/root/chroot_tmpdir/scmroot/ghc-half'...
$ git fetch origin e81d0e536f58a1faff02b7796cfba47f9e209b21:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-half
 * [new ref]         e81d0e536f58a1faff02b7796cfba47f9e209b21 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at e81d0e5 bump release