$ git clone -n https://src.fedoraproject.org/rpms/vala.git /var/lib/mock/f40-build-797035-141053/root/chroot_tmpdir/scmroot/vala
Cloning into '/var/lib/mock/f40-build-797035-141053/root/chroot_tmpdir/scmroot/vala'...
$ git fetch origin 3fc3333af49b90e81361b91f781e9b97f82f1a93:KOJI_FETCH_HEAD
From https://src.fedoraproject.org/rpms/vala
 * [new ref]         3fc3333af49b90e81361b91f781e9b97f82f1a93 -> KOJI_FETCH_HEAD
$ git reset --hard KOJI_FETCH_HEAD
HEAD is now at 3fc3333 Update to 0.56.15