$ git clone -n https://src.fedoraproject.org/rpms/librx.git /var/lib/mock/f41-build-886537-16639/root/chroot_tmpdir/scmroot/librx
Cloning into '/var/lib/mock/f41-build-886537-16639/root/chroot_tmpdir/scmroot/librx'...
$ git fetch origin 1ba2a57c9b9eba9c78ba1e417ce60eb5d0fde62c:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/librx
 * [new ref]         1ba2a57c9b9eba9c78ba1e417ce60eb5d0fde62c -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 1ba2a57 Eliminate use of obsolete %patchN syntax (#2283636)