nx_probe_exhaust_live.nx

nx_probe_exhaust_live.nx -- PROBE (2026-08-05): does nx_cc check MATCH EXHAUSTIVENESS? Three-variant enum, ALL arms present = the valid form. Elm/Rust/Swift refuse this; if this target BUILDS, the check is absent and that is the next enforcement rung (climb v6 rung 1). REPRO A (non-exhaustive): delete the Blue arm -> nx_parse: line N: non-exhaustive match on enum\n// ExhColor: 2 of 3 variants handled -- add an arm for: Blue\n// REPRO B (unreachable): duplicate the Red arm -> nx_parse: line N: unreachable match arm ExhColor::Red\n// -- already handled by an earlier arm of the match at line M\n// license_tier: ORIGINAL expect_exit: 0