regex could not be compiled with either the default regex en

Error message

regex could not be compiled with either the default regex engine or with PCRE2.

default regex engine error:
{divider}
{rust_err}
{divider}

PCRE2 regex engine error:
{pcre_err}

What it means

Error "regex could not be compiled with either the default regex engine or with PCRE2. default regex engine error: {divider} {rust_err} {divider} PCRE2 regex engine error: {pcre_err}" thrown in BurntSushi/ripgrep.

Source

Thrown at crates/core/flags/hiargs.rs:402

                    anyhow::bail!(suggest_other_engine(err.to_string()));
                }
            },
            EngineChoice::PCRE2 => Ok(self.matcher_pcre2()?),
            EngineChoice::Auto => {
                let rust_err = match self.matcher_rust() {
                    Ok(m) => return Ok(m),
                    Err(err) => err,
                };
                log::debug!(
                    "error building Rust regex in hybrid mode:\n{rust_err}",
                );

                let pcre_err = match self.matcher_pcre2() {
                    Ok(m) => return Ok(m),
                    Err(err) => err,
                };
                let divider = "~".repeat(79);
                anyhow::bail!(
                    "regex could not be compiled with either the default \
                     regex engine or with PCRE2.\n\n\
                     default regex engine error:\n\
                     {divider}\n\
                     {rust_err}\n\
                     {divider}\n\n\
                     PCRE2 regex engine error:\n{pcre_err}",
                );
            }
        }
    }

    /// Build a matcher using PCRE2.
    ///
    /// If there was a problem building the matcher (such as a regex syntax
    /// error), then an error is returned.
    ///
    /// If the `pcre2` feature is not enabled then this always returns an

View on GitHub (pinned to 3fce3b5bb0)

Solutions

Fix the regex syntax errors reported by both engines in the message
Test the pattern with a simpler subset to isolate the invalid construct

When it happens

Trigger: Thrown at crates/core/flags/hiargs.rs:402 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of BurntSushi/ripgrep@3fce3b5bb0 (2026-08-06). Data as JSON: /data/errors/e94831bd48b65103.json. Report an issue: GitHub.