$ git clone -n https://src.fedoraproject.org/rpms/ghc-zlib.git /var/lib/mock/f38-build-side-42-init-devel-943781-28778/root/chroot_tmpdir/scmroot/ghc-zlib
Cloning into '/var/lib/mock/f38-build-side-42-init-devel-943781-28778/root/chroot_tmpdir/scmroot/ghc-zlib'...
$ git fetch origin 6dcf50607ed57388c9a5794169298dcc05694821:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/ghc-zlib
 * [new ref]         6dcf50607ed57388c9a5794169298dcc05694821 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6dcf506 drop zlib-0.6.2.3-test-rawformat-s390x-z15.patch