{"record":{"id":"6bfc14e2682571d9","repo":"stamparm/maltrail","slug":"unable-to-compile-the-combined-wildcard-trail-regex-e","errorCode":null,"errorMessage":"unable to compile the combined wildcard-trail regex ({e}); wildcard trail matching is disabled","messagePattern":"unable to compile the combined wildcard-trail regex \\((.+?)\\); wildcard trail matching is disabled","errorType":"console","errorClass":null,"httpStatus":null,"severity":"error","filePath":"sensor/src/trails/regexset.rs","lineNumber":267,"sourceCode":"        self.source.push_str(&format!(\"(?P<g{}>{})\", self.patterns.len(), compiled));\n        self.patterns.push(trail.to_string());\n    }\n\n    pub fn build(self) -> TrailRegex {\n        let mut fancy = false;\n        let regex = if self.source.is_empty() {\n            None\n        } else {\n            let fast = if self.needs_fancy { None } else { pyre::build(&self.source).ok() };\n            match fast {\n                Some(re) => Some(Engine::Fast(re)),\n                None => match pyre::build_fancy(&self.source) {\n                    Ok(re) => {\n                        fancy = true;\n                        Some(Engine::Backtracking(re))\n                    }\n                    Err(e) => {\n                        crate::output::log_error(\n                            &format!(\n                                \"unable to compile the combined wildcard-trail regex ({e}); \\\n                                 wildcard trail matching is disabled\"\n                            ),\n                            true,\n                        );\n                        None\n                    }\n                },\n            }\n        };\n        TrailRegex {\n            regex,\n            patterns: self.patterns,\n            source: self.source,\n            skipped: self.skipped,\n            repaired: self.repaired,\n            fancy,","sourceCodeStart":249,"sourceCodeEnd":285,"githubUrl":"https://github.com/stamparm/maltrail/blob/77cfb06d7606506d101bbcec0786c77166c4255e/sensor/src/trails/regexset.rs#L249-L285","documentation":"The combined regular expression built from all wildcard-trail patterns failed to compile. As a safety measure the sensor disables wildcard trail matching entirely rather than crashing, so trails whose matching depends on this regex engine will not fire until the problem is fixed.","triggerScenarios":"build() calls pyre::build_fancy(&self.source) with the aggregated wildcard-trail pattern and gets Err(e) — usually a pattern that exceeds the backtracking engine's limits or a construct it cannot handle after combination.","commonSituations":"A newly deployed trail set contains a wildcard pattern that produces an over-large or invalid combined regex; regex size/complexity limits exceeded by growing trail counts; an upstream trail feed shipping a pathological pattern.","solutions":["Read the wrapped {e} — it names the regex compile problem (syntax or size/complexity limit) to locate the offending trail pattern.","Bisect the wildcard trail set (remove recent trail additions) until the combined regex compiles, then fix or remove the offending trail.","Reduce wildcard trail complexity (anchor trails, avoid nested/excessive wildcards) to stay under the engine's limits.","Note the operational impact: wildcard trail matching stays disabled until a successful rebuild, so monitor for this log line after every trail update."],"exampleFix":null,"handlingStrategy":"validation","validationCode":"# validate trail patterns before deploying them\n# compile the combined wildcard-trail regex offline and fail the deploy on error\npython3 -c \"import re,sys; re.compile(open(sys.argv[1]).read())\" wildcard_trails.txt || echo \"combined regex invalid\"","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Test the combined wildcard-trail regex in CI before shipping trail updates","Bound wildcard trail complexity; avoid deeply nested or unbounded wildcards","Bisect trail additions when this error appears to find the offending pattern","Monitor for the log line after each trail update — matching stays disabled until a successful rebuild"],"tags":["regex","compilation","trails","degraded"],"backgroundTag":"invalid-regex-pattern","analyzedSha":"77cfb06d7606506d101bbcec0786c77166c4255e","analyzedAt":"2026-09-13T03:50:16.010Z","contentChangedAt":"2026-09-13T03:50:16.010Z","schemaVersion":2},"datasetVersion":"2026-09-16T09:17:16.951Z"}