pbakaus/impeccable · warning

Note: --fast is deprecated and ignored. The full scan is fas

Error message

Note: --fast is deprecated and ignored. The full scan is fast now and runs every rule.

What it means

The detect CLI warns on stderr that the `--fast` flag is deprecated and ignored: the full scan is now fast by default and runs every rule, so `--fast` no longer selects anything. The message is informational only — the scan continues normally with all rules enabled.

Source

Thrown at crates/detect/src/cli.rs:415

fn detect_cli(args_in: &[String], io: &mut Io, engines: &Engines) -> Result<i32, Exit> {
    let mut args: Vec<String> = args_in
        .iter()
        .map(|a| match a.as_str() {
            "-json" => "--json".to_string(),
            "-fast" => "--fast".to_string(),
            _ => a.clone(),
        })
        .collect();
    if args.first().map(String::as_str) == Some("detect") {
        args.remove(0);
    }
    let has = |args: &[String], flag: &str| args.iter().any(|a| a == flag);
    let json_mode = has(&args, "--json");
    let quiet_mode = has(&args, "--quiet");
    let help_mode = has(&args, "--help");
    let no_advisory = has(&args, "--no-advisory");
    if has(&args, "--fast") {
        io.err("Note: --fast is deprecated and ignored. The full scan is fast now and runs every rule.\n");
    }
    if has(&args, "--gpt") || has(&args, "--gemini") {
        io.err("Note: --gpt and --gemini are deprecated and ignored. Generated-UI tells now run by default.\n");
    }
    let config_enabled = !has(&args, "--no-config");
    let cwd = io.cwd.to_string_lossy().into_owned();
    let detection_config = if config_enabled {
        read_detection_config(&cwd)
    } else {
        DetectionConfig::raw()
    };
    let scopes_valid = rule_scopes().join(", ");
    let mut scopes: Vec<String> = Vec::new();
    let mut i = 0;
    while i < args.len() {
        let inline = args[i].starts_with("--scope=");
        if args[i] != "--scope" && !inline {
            i += 1;

View on GitHub (pinned to 2bc2879276)

Solutions

1. Remove `--fast` from the command line / scripts; the default scan is already fast and runs all rules.
2. Update CI configs and docs that reference `--fast` to call `impeccable detect` without the flag.
3. If rule-subset selection is actually needed, use `--scope` instead of `--fast`.

Example fix

// before
impeccable detect src/ --fast
// after
impeccable detect src/

const args = process.argv.slice(2).filter(a => a !== "--fast");

When it happens

Trigger: Passing `--fast` anywhere on the `impeccable detect` command line, detected via `args.iter().any(|a| a == "--fast")`.

Common situations: Scripts or CI configs written against an older CLI version where `--fast` skipped rules; muscle-memory flags carried over from previous workflows; documentation or aliases that still mention `--fast`.

Understand the failure class

Background: "is deprecated and will be removed" — deprecation warnings for old API names, keywords, and options, and how to migrate before the removal release — this error's family across 29 libraries.

Related errors

• Note: --gpt and --gemini are deprecated and ignored. Generat
• Error: --scope requires a value. Valid scopes: {scopes_valid
• Error: --viewport requires a WxH value, e.g. --viewport 390x
• Error: unknown --scope value(s): {}. Valid scopes: {scopes_v
• concept-seed: --candidate-count must be an integer from 5 to

AI-assisted analysis of pbakaus/impeccable@2bc2879276 (2026-09-08). Data as JSON: /api/errors/5d67cdc028fba27a. Report an issue: GitHub.