$ git clone -n https://src.fedoraproject.org/rpms/rust-users.git /var/lib/mock/f42-build-3251826-41222/root/chroot_tmpdir/scmroot/rust-users
Cloning into '/var/lib/mock/f42-build-3251826-41222/root/chroot_tmpdir/scmroot/rust-users'...
$ git fetch origin cd3183c2583898d28c4f0e468f6c285548f49176:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-users
 * [new ref]         cd3183c2583898d28c4f0e468f6c285548f49176 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at cd3183c unmaintained and insecure - superseded by uzers