$ git clone -n https://src.fedoraproject.org/rpms/rust-gst-plugin-json /var/lib/mock/f42-build-3428992-45391/root/chroot_tmpdir/scmroot/rust-gst-plugin-json
Cloning into '/var/lib/mock/f42-build-3428992-45391/root/chroot_tmpdir/scmroot/rust-gst-plugin-json'...
$ git fetch origin 0efe77b25b3fd9c9b63a9972864d6ab6f65ecb75:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/rust-gst-plugin-json
 * [new ref]         0efe77b25b3fd9c9b63a9972864d6ab6f65ecb75 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 0efe77b Initial import