$ git clone -n https://src.fedoraproject.org/rpms/ghc-dotgen.git /var/lib/mock/f41-build-837602-159296/root/chroot_tmpdir/scmroot/ghc-dotgen
Cloning into '/var/lib/mock/f41-build-837602-159296/root/chroot_tmpdir/scmroot/ghc-dotgen'...
$ git fetch origin 3f830323d35cbc4204a8fe17abb3c1070556f345:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-dotgen
 * [new ref]         3f830323d35cbc4204a8fe17abb3c1070556f345 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3f83032 bump release