nx_featassert.nx

nx_featassert.nx -- prove a feature is IN THE BUILT ARTIFACT, not just in the source you meant to edit. WHY THIS EXISTS (operator, 2026-08-07: *"this is a bad bug"*). A whole feature -- writing the gallery's enumerator index -- was never inserted into nx_gen_ingest. A scripted `str.replace` anchor did not match (the source held a LITERAL newline where the pattern had `\n`), and str.replace WITH NO MATCH IS A SILENT NO-OP THAT RETURNS THE ORIGINAL STRING. Then: * the build SUCCEEDED -- absent code has no failure mode, * the run printed 10 NEW / 10 idx:INSERTED -- everything still present worked perfectly, * nothing anywhere in compile-or-test was watching for work that was never emitted. ★★★★★★ A MISSING FEATURE PRODUCES A CLEAN BUILD AND A GREEN RUN. YOU CANNOT TEST FOR THE ABSENCE OF CODE BY RUNNING THE CODE. The doctrine fix ("always assert your anchor matched") is the weak one: it relies on remembering, and forgetting is exactly what happened. THE MECHANICAL FIX IS THAT A FEATURE MUST BE PROVABLE IN THE ARTIFACT. A feature that was never compiled in has no marker string in the binary. So: nx_featassert _build/nx_gen_ingest.sov.elf "view:ADDED" is the one check that would have caught it, and it costs a substring scan. A marker prefixed with '!' must be ABSENT -- which makes this prove a REMOVAL too, and gives the tool its own negative control (a checker that returns PRESENT for everything scores 100%). Usage: nx_featassert <artifact> <marker> [<marker> ...] '!marker' = must NOT be present Exit 0 = every assertion held; 1 = at least one failed; 2 = usage; 3 = unreadable. license_tier: ORIGINAL