$ git clone -n https://src.fedoraproject.org/rpms/ghc-mwc-random.git /var/lib/mock/f38-build-side-42-init-devel-1117587-30186/root/chroot_tmpdir/scmroot/ghc-mwc-random
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-1117587-30186/root/chroot_tmpdir/scmroot/ghc-mwc-random'...
$ git fetch origin fb00e7377168e839e1d3ab9da393160263499d79:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-mwc-random
 * [new ref]         fb00e7377168e839e1d3ab9da393160263499d79 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at fb00e73 Convert to %autorelease and %autochangelog