From 42b81d7b04a4f045a9a2a813a63bbe3a34795e16 Mon Sep 17 00:00:00 2001
From: Matt <47545907+SoundMatt@users.noreply.github.com>
Date: Fri, 21 Aug 2026 07:29:58 -0700
Subject: [PATCH] ci: gate on relay interop's real exit code instead of
 grep-scraping stdout

Replaces `interop_out=$(relay interop ... 2>&1) || true` + a grep of
stdout for ERROR/FAIL with a plain `relay interop --strict --protocol
LIN ./target/release/rust-lin` invocation whose real exit code gates
the step directly. The old form silently tolerated both a genuinely
broken run and any future change to relay interop's output format,
since `|| true` swallowed the real exit code before the grep ever ran.

--protocol LIN restricts the check to rust-lin's own protocol and
--strict fails on a missing convert rather than treating it as an
innocuous skip -- matching the pattern already fixed in rust-RCP
(SoundMatt/rust-RCP#171) and go-RCP/go-LIN's existing clean form.

The surrounding job is already correctly named 'conformance' (not
'interop'), so no rename needed here, unlike rust-RCP's fix.

Verified locally against the exact relay v2.0.4 build this job
installs: a real rust-lin binary produces RESULT: PASS / exit 0;
mutation-tested against a deliberately broken binary, confirmed
RESULT: FAIL / exit 1 (the previous || true form would have swallowed
this). Also confirmed no job-id collisions exist in this workflow
(5 unique job ids, none duplicated) before pushing, after the
job-collision bug found while fixing rust-RCP's identical pattern.

SoundMatt/RELAY THEME-K (#125) / INTEROP-04 (#149).

Signed-off-by: Matt <47545907+SoundMatt@users.noreply.github.com>
---
 .github/workflows/ci.yml | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 1a7d374..b2cfad4 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -278,14 +278,18 @@ jobs:
       - name: RELAY conformance (strict)
         run: relay conform --strict ./target/release/rust-lin
 
-      - name: RELAY interop (LIN golden vectors — must be EQUIVALENT)
-        run: |
-          interop_out=$(relay interop ./target/release/rust-lin 2>&1) || true
-          echo "$interop_out"
-          if echo "$interop_out" | grep -A2 "(LIN)" | grep -qE "ERROR|FAIL"; then
-            echo "FAIL: one or more LIN golden vectors not EQUIVALENT"
-            exit 1
-          fi
+      - name: RELAY interop --strict --protocol LIN (LIN golden vectors — must be EQUIVALENT)
+        # Was previously `interop_out=$(relay interop ... 2>&1) || true` piped
+        # through a grep of stdout instead of the command's real exit code —
+        # that silently tolerated both a genuinely broken run and any future
+        # change to relay interop's output format (SoundMatt/RELAY THEME-K,
+        # INTEROP-04). --protocol LIN restricts the check to rust-lin's own
+        # protocol and --strict fails on a missing convert rather than
+        # treating it as an innocuous skip; the command's real exit code now
+        # gates this step directly, verified locally against the pinned
+        # relay v2.0.4 build this job installs (EQUIVALENT/PASS/exit 0 on a
+        # real convert implementation, FAIL/exit 1 on a broken one).
+        run: relay interop --strict --protocol LIN ./target/release/rust-lin
 
   # ── DCO sign-off check ─────────────────────────────────────────────────────
   dco: