{"record":{"id":"633fc372385db894","repo":"github/copilot-sdk","slug":"failed-to-read-existing-go-file-w","errorCode":null,"errorMessage":"failed to read existing Go file: %w","messagePattern":"failed to read existing Go file: %w","errorType":"console","errorClass":null,"httpStatus":null,"severity":"error","filePath":"go/cmd/bundler/main.go","lineNumber":1296,"sourceCode":"\tif err != nil {\n\t\treturn fmt.Errorf(\"failed to add zstd dependency: %w\\n%s\", err, strings.TrimSpace(string(output)))\n\t}\n\treturn nil\n}\n\n// checkEmbeddedVersion checks if an embedded CLI version exists and compares it with the detected version.\nfunc checkEmbeddedVersion(detectedVersion, goos, goarch, outputDir string) error {\n\t// Look for the generated Go file for this platform\n\tgoFileName := fmt.Sprintf(\"zcopilot_%s_%s.go\", goos, goarch)\n\tgoFilePath := filepath.Join(outputDir, goFileName)\n\n\tdata, err := os.ReadFile(goFilePath)\n\tif err != nil {\n\t\tif os.IsNotExist(err) {\n\t\t\t// No existing embedded version, nothing to check\n\t\t\treturn nil\n\t\t}\n\t\treturn fmt.Errorf(\"failed to read existing Go file: %w\", err)\n\t}\n\n\t// Extract version from the generated file\n\t// Looking for: Version: \"x.y.z\",\n\tre := regexp.MustCompile(`Version:\\s*\"([^\"]+)\"`)\n\tmatches := re.FindSubmatch(data)\n\tif matches == nil {\n\t\t// Can't parse version, skip check\n\t\treturn nil\n\t}\n\n\tembeddedVersion := string(matches[1])\n\tfmt.Printf(\"Found existing embedded version: %s\\n\", embeddedVersion)\n\n\t// Compare versions\n\tif embeddedVersion != detectedVersion {\n\t\treturn fmt.Errorf(\"embedded version %s does not match detected version %s - update required\", embeddedVersion, detectedVersion)\n\t}","sourceCodeStart":1278,"sourceCodeEnd":1314,"githubUrl":"https://github.com/github/copilot-sdk/blob/cd8cf15dc3f9e762615790aaed0a771a0f392755/go/cmd/bundler/main.go#L1278-L1314","documentation":"checkEmbeddedVersion reads the previously generated Go file that records the embedded CLI version. If os.ReadFile fails for any reason other than the file not existing (IsNotExist returns early with nil), the error is wrapped with this message. It means an existing version file is present but unreadable.","triggerScenarios":"os.ReadFile on goFilePath fails with a permission error, the path is a directory, or an I/O error occurs — any non-ENOENT failure. The IsNotExist case is intentionally tolerated (nothing to check).","commonSituations":"File locked down by a previous build running as another user; path is now a directory due to layout change; stale build artifacts on a failing disk or read-only mounted output dir.","solutions":["Check the wrapped underlying error for the exact cause (permission vs EISDIR vs I/O)","Fix file permissions on the generated Go file (chown/chmod) or run the bundler as the file's owner","If the path became a directory, remove it or update goFilePath generation","Delete the stale file so the next run regenerates it (the not-exist path is tolerated)"],"exampleFix":"// before\nreturn fmt.Errorf(\"failed to read existing Go file: %w\", err)\n// after\nreturn fmt.Errorf(\"failed to read existing Go file %s: %w\", goFilePath, err) // include path to ease diagnosis","handlingStrategy":"try-catch","validationCode":"// check readability before bundler runs\nif _, err := os.ReadFile(goFilePath); err != nil && !os.IsNotExist(err) {\n\t// fix permissions/path beforehand\n}","typeGuard":null,"tryCatchPattern":"// Go\nif err := checkEmbeddedVersion(detected, goos, goarch, outDir); err != nil {\n\tif errors.Is(err, fs.ErrPermission) { /* chown/chmod and retry */ }\n}","preventionTips":["Run bundler steps as a single consistent user","Do not hand-edit generated files","Keep build output directories free of stale artifacts"],"tags":["filesystem","file-read","go"],"backgroundTag":"file-read-failed","analyzedSha":"cd8cf15dc3f9e762615790aaed0a771a0f392755","analyzedAt":"2026-09-09T18:32:31.973Z","contentChangedAt":"2026-09-09T18:32:31.973Z","schemaVersion":2},"datasetVersion":"2026-09-15T23:17:13.987Z"}