$ git clone -n https://src.fedoraproject.org/rpms/ghc-connection.git /var/lib/mock/f39-build-1716068-41229/root/chroot_tmpdir/scmroot/ghc-connection
Cloning into '/var/lib/mock/f39-build-1716068-41229/root/chroot_tmpdir/scmroot/ghc-connection'...
$ git fetch origin 4d64821697ff37e71a18f2a1af7c9775828d571d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-connection
 * [new ref]         4d64821697ff37e71a18f2a1af7c9775828d571d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 4d64821 revised .cabal file