$ git clone -n https://src.fedoraproject.org/rpms/R-filelock.git /var/lib/mock/f43-build-58895113-6569073/root/chroot_tmpdir/scmroot/R-filelock
Cloning into '/var/lib/mock/f43-build-58895113-6569073/root/chroot_tmpdir/scmroot/R-filelock'...
$ git fetch origin c666947a3471e85918faecf09cf7cda2c19675d9:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/R-filelock
 * [new ref]         c666947a3471e85918faecf09cf7cda2c19675d9 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at c666947 R-maint-sig mass rebuild