Class stat

tests/repro/repro_issue570.c:204–204

    /* Building the plan must not have created any actual config files. */
    struct stat st;
    char cfg[512];
    snprintf(cfg, sizeof(cfg), "%s/.codex/config.toml", home);
    ASSERT(stat(cfg, &st) != 0); /* config.toml must NOT have been created */