$ git clone -n https://src.fedoraproject.org/rpms/ghc-vector-th-unbox.git /var/lib/mock/f38-build-side-42-init-devel-826531-28364/root/chroot_tmpdir/scmroot/ghc-vector-th-unbox
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-826531-28364/root/chroot_tmpdir/scmroot/ghc-vector-th-unbox'...
$ git fetch origin ea6db66df5c5e196244466a15bbe19c97580d863:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-vector-th-unbox
 * [new ref]         ea6db66df5c5e196244466a15bbe19c97580d863 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ea6db66 Convert to %autorelease and %autochangelog