$ git clone -n https://src.fedoraproject.org/forks/hypersa/rpms/ghc-regex-tdfa.git /var/lib/mock/f39-build-2218574-52612/root/chroot_tmpdir/scmroot/ghc-regex-tdfa
Cloning into '/var/lib/mock/f39-build-2218574-52612/root/chroot_tmpdir/scmroot/ghc-regex-tdfa'...
$ git fetch origin ac188023595e2b2943785347e395e5f8782b31d6:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/forks/hypersa/rpms/ghc-regex-tdfa
 * [new ref]         ac188023595e2b2943785347e395e5f8782b31d6 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at ac18802 rv64 rebuild