fix: silence NoFallbackError in router-server outer catch#90554
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sleitor wants to merge 1 commit intovercel:canaryfrom
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fix: silence NoFallbackError in router-server outer catch#90554sleitor wants to merge 1 commit intovercel:canaryfrom
sleitor wants to merge 1 commit intovercel:canaryfrom
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NoFallbackError is internal control-flow used by dynamicParams=false routes to signal that an unknown param has no static rendering. It is caught and handled inside handleRequest (producing the correct 404 response), but in some edge cases (e.g. when the not-found page itself triggers the error) it can propagate to the outer catch block where it was previously logged via console.error and served as a 500. This produces false-positive error alerts in APM tools (Datadog dd-trace, Sentry, New Relic) that intercept console.error, flooding dashboards with noise on every bot crawl of a dynamicParams=false route. Fix: treat NoFallbackError in the outer catch as a 404 (not 500) and skip the console.error call, since it is not a real application error. Fixes vercel#90537
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What?
Prevent
NoFallbackErrorfrom being logged viaconsole.errorin the outer catch block ofrouter-server.ts, and treat it as a 404 (not a 500).Why?
NoFallbackErroris internal control-flow — thrown bydynamicParams = falseroutes when an unknown param is requested. It is caught and handled insidehandleRequest(correctly producing a 404 response), but in edge cases (e.g. when the not-found page itself triggers the error) it can propagate to the outer catch block.Previously, the outer catch logged it via
console.errorand attempted to serve a 500 response. This causes:console.errorand report every bot crawl of adynamicParams = falseroute as an application error.NoFallbackErroris semantically a 404, not a 500.How?
Added an
else if (err instanceof NoFallbackError)branch before theconsole.errorcall. When matched, it setsinvokePath = '/404'andinvokeStatus = '404'without logging.Fixes #90537