$ git clone -n https://src.fedoraproject.org/rpms/rust-gstreamer-pbutils /var/lib/mock/f42-build-3429004-45391/root/chroot_tmpdir/scmroot/rust-gstreamer-pbutils
Cloning into '/var/lib/mock/f42-build-3429004-45391/root/chroot_tmpdir/scmroot/rust-gstreamer-pbutils'...
$ git fetch origin c498015e90685132d1bb8ed02da2504b429cc26e:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gstreamer-pbutils
 * [new ref]         c498015e90685132d1bb8ed02da2504b429cc26e -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c498015 Update to version 0.23.5; Fixes RHBZ#2333676