{"record":{"id":"b8f0e74a66d3b2d9","repo":"cloudflare/cloudflared","slug":"error-copying-file-s-w","errorCode":null,"errorMessage":"error copying file %s: %w","messagePattern":"error copying file (.+?): %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"diagnostic/log_collector_utils.go","lineNumber":96,"sourceCode":"\t}\n\n\t// nolint: gosec\n\toutputHandle, err := os.Create(filepath.Join(os.TempDir(), logFilename))\n\tif err != nil {\n\t\treturn \"\", fmt.Errorf(\"creating temporary log file %s: %w\", logFilename, err)\n\t}\n\tdefer func() { _ = outputHandle.Close() }()\n\n\tfor _, file := range files {\n\t\t// nolint: gosec\n\t\tlogHandle, err := os.Open(filepath.Join(path, file.Name()))\n\t\tif err != nil {\n\t\t\treturn \"\", fmt.Errorf(\"error opening file %s: %w\", file.Name(), err)\n\t\t}\n\t\t_, err = io.Copy(outputHandle, logHandle)\n\t\t_ = logHandle.Close()\n\t\tif err != nil {\n\t\t\treturn \"\", fmt.Errorf(\"error copying file %s: %w\", file.Name(), err)\n\t\t}\n\t}\n\n\t// nolint: gosec\n\tlogHandle, err := os.Open(filepath.Join(path, defaultLogFilename))\n\tif err != nil {\n\t\treturn \"\", fmt.Errorf(\"error opening file %s:%w\", defaultLogFilename, err)\n\t}\n\tdefer func() { _ = logHandle.Close() }()\n\n\t_, err = io.Copy(outputHandle, logHandle)\n\tif err != nil {\n\t\treturn \"\", fmt.Errorf(\"error copying file %s:%w\", logHandle.Name(), err)\n\t}\n\n\treturn outputHandle.Name(), nil\n}\n","sourceCodeStart":78,"sourceCodeEnd":114,"githubUrl":"https://github.com/cloudflare/cloudflared/blob/2253eeeb25a44a713a4b60b8ba1e1b3f377d1a0f/diagnostic/log_collector_utils.go#L78-L114","documentation":"Wrapped io.Copy failure inside the per-file loop of diagnostic CopyFilesFromDirectory: reading a rolling log file or writing it into the temporary merged log failed mid-copy, so the collected log bundle would be incomplete and the operation aborts.","triggerScenarios":"os.Open(filepath.Join(path, defaultLogFilename)) fails: cloudflared.log (default) missing from the directory, unreadable, or directory contents changed during collection.","commonSituations":"Log directory exists but the main log file was renamed/rotated away; fresh install where cloudflared never wrote its default log; permission restrictions on the main log.","solutions":["Verify the default log file (cloudflared.log) exists in the directory and is readable","Ensure cloudflared is running/logging so the default log file is created","Re-run the diagnostic after confirming log directory contents (ls -l <path>)"],"exampleFix":"// before\ncollect from /var/log/cloudflared  # cloudflared.log absent\n// after\n# confirm logging output path first\nls -l /var/log/cloudflared/cloudflared.log || systemctl restart cloudflared","handlingStrategy":"fallback","validationCode":"defaultLog := filepath.Join(logDir, \"cloudflared.log\")\nif _, err := os.Stat(defaultLog); err != nil {\n\treturn errors.New(\"default log file missing; ensure cloudflared is running and logging\")\n}","typeGuard":"func defaultLogExists(logDir, name string) bool {\n\t_, err := os.Stat(filepath.Join(logDir, name))\n\treturn err == nil\n}","tryCatchPattern":"out, err := diagnostic.CopyFilesFromDirectory(ctx, fs, logDir, logFilename)\nif err != nil && strings.Contains(err.Error(), \"error opening file\") {\n\t// proceed with whatever partial bundle exists or surface actionable message\n}","preventionTips":["Verify the default log file exists before running diagnostics","Ensure cloudflared service is running so it writes its default log","Use --logfile config consistently so the default filename is stable"],"tags":["filesystem","file-open","diagnostics"],"backgroundTag":"file-not-found","analyzedSha":"2253eeeb25a44a713a4b60b8ba1e1b3f377d1a0f","analyzedAt":"2026-09-06T04:14:33.757Z","contentChangedAt":"2026-09-06T04:14:33.757Z","schemaVersion":2},"datasetVersion":"2026-09-14T00:17:10.932Z"}