# Convention: illumos ELF and RUNPATH

illumos linking is not Linux linking. Recipes that assume glibc/Linux behaviour
break.

- **libc is illumos libc**, not glibc. Don't assume glibc-only symbols, headers,
  or `/lib/x86_64-linux-gnu` layouts.
- **Library resolution is via RUNPATH** in the ELF. Set it correctly so the
  binary finds its own closure. `$ORIGIN` is supported and is the right tool for
  relocatable `$out/lib` layouts.
- **`NEEDED` must be satisfiable** from the recorded references. The cache
  classifier won't publish a leaf whose closure can't resolve.
- **Build inputs legitimately reference `/usr`.** Seeds and the gate-proto point
  at `/usr` by design — that's correct for a build input, not a defect. They are
  a protected durability class and are **not** judged by the leaf-installability
  gate. If you're packaging an input, don't try to scrub `/usr` out of it.
- **Sections differ.** illumos man pages use sections like `1m` (admin),
  `3c`/`3*`, `7d`, `9*`. Ship them under `share/man/manN` accordingly.

The publication validator does **not** enforce RUNPATH/NEEDED itself — that
audit is the build team's. But if the closure doesn't resolve on a real system,
the package is not installable and won't survive classification.