Function build_robustness

tests/repro/repro_grammar_build.c:395–409

── Robustness helper: assert call RETURNS on malformed input ─────────────── * * A truncated version of the fixture is passed through cbm_extract_file. * has_error may be set (1) but the call must return non-NULL. If it returns * NULL the extractor crashed or aborted on bad input -- that is a RED * robustness bug. Returns 0 on PASS, 1 on FAIL. */

 * robustness bug. Returns 0 on PASS, 1 on FAIL.
 */
static int build_robustness(const char *lang_tag, const char *bad_src,
                            CBMLanguage lang, const char *file) {
    const char *RED = tf_red();
    const char *RST = tf_reset();

    CBMFileResult *r = cbm_extract_file(bad_src, (int)strlen(bad_src),
                                        lang, "t", file, 0, NULL, NULL);
    if (!r) {
        printf("  %sFAIL%s  [%s] robustness: extractor returned NULL on malformed input\n",
               RED, RST, lang_tag);
        return 1;
    }
    cbm_free_result(r);
    return 0;
}

/* ── Dockerfile ───────────────────────────────────────────────────────────────
 * Idiomatic two-stage Dockerfile: a builder stage (FROM ... AS ...) followed by