cocoindex-io/cocoindex · critical

invalid exclude_reference_patterns regex

Error message

invalid exclude_reference_patterns regex

What it means

Building a Config element, the exclude_reference_patterns entries are combined into a single anchored regex; if that combined pattern is not a valid regex, Regex::new panics via .expect("invalid exclude_reference_patterns regex"). Because patterns are wrapped as (?:p) and joined with |, an individually valid-looking pattern can still fail or the combined alternation can exceed regex limits.

Source

Thrown at rust/code_ast/src/elements/config.rs:134

}

impl CompiledLanguageConfig {
    fn new(config: LanguageExtractorConfig) -> Self {
        let exclude_regex = if config.exclude_reference_patterns.is_empty() {
            None
        } else {
            // Each pattern is wrapped in a non-capturing group and the whole expression
            // is anchored with ^ and $ so patterns match the full `referenced_full_path`.
            // Users write e.g. `[A-Z]` instead of `^[A-Z]$`.
            let alternatives: Vec<String> = config
                .exclude_reference_patterns
                .iter()
                .map(|p| format!("(?:{p})"))
                .collect();
            let combined = alternatives.join("|");
            Some(
                Regex::new(&format!("^(?:{combined})$"))
                    .expect("invalid exclude_reference_patterns regex"),
            )
        };
        Self {
            config,
            exclude_regex,
        }
    }

    /// Returns true if the given `referenced_full_path` should be excluded.
    pub fn is_excluded(&self, full_path: &str) -> bool {
        self.exclude_regex
            .as_ref()
            .is_some_and(|re| re.is_match(full_path))
    }
}

// ── ExtractorConfig ────────────────────────────────────────────────────────

View on GitHub (pinned to e84aa99b32)

Solutions

1. Validate each pattern with Regex::new in a scratch test or an online regex checker (Rust/regex syntax) before configuring.
2. Escape regex metacharacters for literal matching (use \. for dots, \* etc.).
3. Split an overly large exclusion list into multiple configs or simplify patterns to reduce compiled size.
4. Remove the offending pattern from exclude_reference_patterns and rerun.

Example fix

// before
exclude_reference_patterns: ["*.pyc"]  // invalid regex

// after
exclude_reference_patterns: [".*\\.pyc"]

// validate patterns before configuring
for p in &patterns {
    regex::Regex::new(&format!("(?:{p})")).expect(&format!("bad pattern: {p}"));
}

When it happens

Trigger: Passing a syntactically invalid regex string in exclude_reference_patterns (e.g. "[unclosed", "a)**"), or a set of patterns whose combined alternation is invalid or too large for the regex crate's compiled-size limit.

Common situations: Users copying shell globs (e.g. "*.py") where regex is expected without escaping the `*`; typos in character classes; very long exclusion lists blowing the default regex size cap.

Related errors

• valid tokenizer regex
• Environment::provide: type `{}` has already been provided
• Environment::provide_key({}): {e}
• with_base_url must be called before the connection is shared
• Invalid Neo4j database name: {database!r}. Must match [A-Za-

AI-assisted analysis of cocoindex-io/cocoindex@e84aa99b32 (2026-09-08). Data as JSON: /api/errors/4ce71cd5198dea83. Report an issue: GitHub.