$ git clone -n https://src.fedoraproject.org/rpms/ghc-servant-client-core.git /var/lib/mock/f39-build-1969527-43314/root/chroot_tmpdir/scmroot/ghc-servant-client-core
Cloning into '/var/lib/mock/f39-build-1969527-43314/root/chroot_tmpdir/scmroot/ghc-servant-client-core'...
$ git fetch origin 19c768ba198b2906efb66a910fa3ac7d9501d288:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-servant-client-core
 * [new ref]         19c768ba198b2906efb66a910fa3ac7d9501d288 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 19c768b revised .cabal file