$ git clone -n https://src.fedoraproject.org/rpms/rust-gstreamer0.21.git /var/lib/mock/f40-build-59022463-6570255/root/chroot_tmpdir/scmroot/rust-gstreamer0.21
Cloning into '/var/lib/mock/f40-build-59022463-6570255/root/chroot_tmpdir/scmroot/rust-gstreamer0.21'...
$ git fetch origin 0ff9a78d5c7914b072dfb2d255c8346f00780f6d:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gstreamer0.21
 * [new ref]         0ff9a78d5c7914b072dfb2d255c8346f00780f6d -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0ff9a78 Bump ron dev-dependency from 0.8 to 0.9