$ git clone -n https://src.fedoraproject.org/rpms/rust-sysinfo0.23.git /var/lib/mock/f42-build-3367108-45050/root/chroot_tmpdir/scmroot/rust-sysinfo0.23
Cloning into '/var/lib/mock/f42-build-3367108-45050/root/chroot_tmpdir/scmroot/rust-sysinfo0.23'...
$ git fetch origin 6560bb81fa81828296da6dd559c855e8fe708d3b:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-sysinfo0.23
 * [new ref]         6560bb81fa81828296da6dd559c855e8fe708d3b -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 6560bb8 compat package no longer needed