$ git clone -n https://src.fedoraproject.org/rpms/rust-gstreamer-pbutils.git /var/lib/mock/f38-build-side-43-rust-devel-1403578-31197/root/chroot_tmpdir/scmroot/rust-gstreamer-pbutils
Cloning into '/var/lib/mock/f38-build-side-43-rust-devel-1403578-31197/root/chroot_tmpdir/scmroot/rust-gstreamer-pbutils'...
$ git fetch origin dc50605e5fd5a1a6f0b693cb4de5114c7c231e2f:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gstreamer-pbutils
 * [new ref]         dc50605e5fd5a1a6f0b693cb4de5114c7c231e2f -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at dc50605 Update to 0.21.0