What causes "(?:https?|ftp)://\S+|www\.\S+" in Kuberwastaken/claurst?

If this panic occurred, the pattern string in `links_url_regex` was modified — revert or fix the regex syntax.

(?:https?|ftp)://\S+|www\.\S+

Error message

(?:https?|ftp)://\S+|www\.\S+

What it means

This panic wraps construction of the static URL-detection regex used by the /links command: `regex::Regex::new(r"(?:https?|ftp)://\S+|www\.\S+").expect(...)`. The pattern is a compile-time constant and is valid, so the expect should never fire; it exists because Regex::new returns a Result that must be handled inside the Lazy initializer.

Solutions

If this panic occurred, the pattern string in `links_url_regex` was modified — revert or fix the regex syntax.
Validate regex changes in a test (`Regex::new(PATTERN).unwrap()` in a unit test) so breakage is caught by `cargo test`, not at runtime.
Prefer `once_cell::sync::Lazy` with a checked pattern plus a debug_assert, or move validation to a compile-time check.
Keep the error message distinct (`"links URL regex"`) so the panicking constant is easy to locate.

Example fix

// before
static URL_RE: once_cell::sync::Lazy<regex::Regex> = once_cell::sync::Lazy::new(|| {
    regex::Regex::new(r"(?:https?|ftp)://\S+|www\.\S+").expect("links URL regex")
});
// after (test guarding the constant)
#[test]
fn links_url_regex_is_valid() {
    links_url_regex();
}

Defensive patterns

Strategy: validation

Validate before calling

// Compile-time-ish guard: unit test asserting the constant parses
#[test]
fn links_url_regex_compiles() {
    regex::Regex::new(r"(?:https?|ftp)://\S+|www\.\S+").unwrap();
}

Prevention

Never edit the regex constant without running the regex-compiles unit test
Keep the descriptive expect message so the failing constant is identifiable
Validate regex syntax locally with `regex-cli` or a quick `Regex::new` snippet before committing

When it happens

Trigger: Practically unreachable: calling `links_url_regex()` (via `extract_session_urls`) only panics if the hard-coded regex string was edited into an invalid pattern, since the Lazy static is built on first use.

Common situations: A developer edits the URL pattern and introduces a syntax error (unbalanced group, bad escape); the panic then fires on the first /links invocation rather than at compile time.

Related errors

AI-assisted analysis of Kuberwastaken/claurst@b0637c97ec (2026-09-10). Data as JSON: /api/errors/7a9cb52fedd15d33. Report an issue: GitHub.

Appendix: source

Thrown at src-rust/crates/commands/src/share.rs:145

        } else if opted_out {
            "The gist is secret (unlisted). Anyone with the link can view it; delete the gist to revoke access."
        } else {
            "Could not auto-open the link. Copy the URL above. The gist is secret (unlisted); delete the gist to revoke access."
        };

        CommandResult::Message(format!(
            "Share URL: {viewer}\nGist: {gist_url}\n\n{footer}"
        ))
    }
}

// ---- /links --------------------------------------------------------------

/// Detect URLs in plain text. Mirrors the styling regex in tui::messages::markdown
/// so the user sees the same links the renderer highlights.
fn links_url_regex() -> &'static regex::Regex {
    static URL_RE: once_cell::sync::Lazy<regex::Regex> = once_cell::sync::Lazy::new(|| {
        regex::Regex::new(r"(?:https?|ftp)://\S+|www\.\S+").expect("links URL regex")
    });
    &URL_RE
}

fn strip_trailing_punct(url: &str) -> String {
    let mut s = url.to_string();
    while let Some(c) = s.chars().last() {
        if matches!(c, '.' | ',' | ';' | ':' | '!' | '?' | ')' | ']' | '}' | '\'' | '"' | '>') {
            s.pop();
        } else {
            break;
        }
    }
    s
}

/// Walk messages (oldest → newest), pulling text out of each block and
/// returning unique URLs in *most-recent-first* order.

View on GitHub (pinned to b0637c97ec)