$ git clone -n https://src.fedoraproject.org/rpms/ghc-path-pieces.git /var/lib/mock/f40-build-742270-110680/root/chroot_tmpdir/scmroot/ghc-path-pieces
Cloning into '/var/lib/mock/f40-build-742270-110680/root/chroot_tmpdir/scmroot/ghc-path-pieces'...
$ git fetch origin d66a2c990d881c4d7c4424d2fba567da4c4d8382:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-path-pieces
 * [new ref]         d66a2c990d881c4d7c4424d2fba567da4c4d8382 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at d66a2c9 bump release