$ git clone -n https://src.fedoraproject.org/rpms/ghc-th-orphans.git /var/lib/mock/f38-build-721717-98611/root/chroot_tmpdir/scmroot/ghc-th-orphans
Cloning into '/var/lib/mock/f38-build-721717-98611/root/chroot_tmpdir/scmroot/ghc-th-orphans'...
$ git fetch origin 7e0bdb13453b41f4f96f2560baa74ffc542a0421:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-th-orphans
 * [new ref]         7e0bdb13453b41f4f96f2560baa74ffc542a0421 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 7e0bdb1 Convert to %autorelease and %autochangelog