Packaged base packages are created by running the stageworld and stagekernel targets with -DNO_ROOT, and converting the resulting mtree file into a set of pkg plists. If stage* is run with multiple processes the order of entries in the mtree file may be nondeterministic, and the resulting package tbz also had nondeterministic file ordering.

The mtree file generated by -DNO_ROOT builds consists of one line per file, with the filename starting in the first column, so is easily sorted. There's one exception: the first line of the mtree file is a comment, but the # character sorts before the filenames anyhow and needs no special treatment.