{"record":{"id":"b62e653a27682abe","repo":"vercel/next.js","slug":"unknown-source-map-type-for-filename-buffer","errorCode":null,"errorMessage":"Unknown source map type for ${filename}: ${buffer.typeFull}.","messagePattern":"Unknown source map type for (.+?): (.+?)\\.","errorType":"exception","errorClass":"Error","httpStatus":null,"severity":"error","filePath":"packages/next/src/server/dev/get-source-map-from-file.ts","lineNumber":58,"sourceCode":"  const sourceUrl = getSourceMapUrl(fileContents)\n\n  if (!sourceUrl) {\n    return undefined\n  }\n\n  if (sourceUrl.startsWith('data:')) {\n    let buffer: dataUriToBuffer.MimeBuffer\n\n    try {\n      buffer = dataUriToBuffer(sourceUrl)\n    } catch (error) {\n      throw new Error(`Failed to parse source map URL for ${filename}.`, {\n        cause: error,\n      })\n    }\n\n    if (buffer.type !== 'application/json') {\n      throw new Error(\n        `Unknown source map type for ${filename}: ${buffer.typeFull}.`\n      )\n    }\n\n    try {\n      return JSON.parse(buffer.toString())\n    } catch (error) {\n      throw new Error(`Failed to parse source map for ${filename}.`, {\n        cause: error,\n      })\n    }\n  }\n\n  const sourceMapFilename = path.resolve(\n    path.dirname(filename),\n    decodeURIComponent(sourceUrl)\n  )\n","sourceCodeStart":40,"sourceCodeEnd":76,"githubUrl":"https://github.com/vercel/next.js/blob/0eb377541648e63402a47b38fee00a8d0ce8f8f1/packages/next/src/server/dev/get-source-map-from-file.ts#L40-L76","documentation":"Content-type check on an inline source map: the decoded data: URI buffer's MIME type is not application/json, so it cannot be a valid source map payload. It indicates the data URI was mis-decoded or the artifact embeds a non-JSON payload where a map should be.","triggerScenarios":"A source map has an unrecognized type.","commonSituations":"A third-party tool emits a source map format the dev server does not understand.","solutions":["Provide a source map as a JSON file or data URL; the detected type is unsupported."],"exampleFix":null,"handlingStrategy":"validation","validationCode":null,"typeGuard":null,"tryCatchPattern":null,"preventionTips":[],"tags":[],"backgroundTag":null,"analyzedSha":"0eb377541648e63402a47b38fee00a8d0ce8f8f1","analyzedAt":"2026-08-19T02:10:13.922Z","contentChangedAt":"2026-08-19T02:10:13.922Z","schemaVersion":2},"datasetVersion":"2026-09-23T08:17:48.524Z"}