$ git clone -n https://src.fedoraproject.org/rpms/ghc-zenc.git /var/lib/mock/f41-build-838853-159865/root/chroot_tmpdir/scmroot/ghc-zenc
Cloning into '/var/lib/mock/f41-build-838853-159865/root/chroot_tmpdir/scmroot/ghc-zenc'...
$ git fetch origin bcc0c17346f432e936dcba2d9acba1b645421ca9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-zenc
 * [new ref]         bcc0c17346f432e936dcba2d9acba1b645421ca9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at bcc0c17 bump release