$ git clone -n https://src.fedoraproject.org/rpms/ghc-GLUT.git /var/lib/mock/f41-build-839298-160118/root/chroot_tmpdir/scmroot/ghc-GLUT
Cloning into '/var/lib/mock/f41-build-839298-160118/root/chroot_tmpdir/scmroot/ghc-GLUT'...
$ git fetch origin 1530ce9df0a0f74cf59d04f23cd2a0d1dcbd4fa0:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-GLUT
 * [new ref]         1530ce9df0a0f74cf59d04f23cd2a0d1dcbd4fa0 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1530ce9 revise .cabal file