$ git clone -n https://src.fedoraproject.org/rpms/mtr.git /var/lib/mock/f40-build-802773-144093/root/chroot_tmpdir/scmroot/mtr
Cloning into '/var/lib/mock/f40-build-802773-144093/root/chroot_tmpdir/scmroot/mtr'...
$ git fetch origin b86ff741445b33f15dc41f6dfa9c72c01dbf0db1:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/mtr
 * [new ref]         b86ff741445b33f15dc41f6dfa9c72c01dbf0db1 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at b86ff74 Added upstream patch to fix '--address' with policy-based routing