{"record":{"id":"fb2f062d58680e87","repo":"hyperledger/fabric","slug":"error-writing-config-update-to-output","errorCode":null,"errorMessage":"error writing config update to output","messagePattern":"error writing config update to output","errorType":"console","errorClass":null,"httpStatus":null,"severity":"error","filePath":"cmd/configtxlator/main.go","lineNumber":230,"sourceCode":"\tif err != nil {\n\t\treturn errors.Wrapf(err, \"error unmarshalling updated config\")\n\t}\n\n\tcu, err := update.Compute(origConf, updtConf)\n\tif err != nil {\n\t\treturn errors.Wrapf(err, \"error computing config update\")\n\t}\n\n\tcu.ChannelId = channelID\n\n\toutBytes, err := proto.Marshal(cu)\n\tif err != nil {\n\t\treturn errors.Wrapf(err, \"error marshaling computed config update\")\n\t}\n\n\t_, err = output.Write(outBytes)\n\tif err != nil {\n\t\treturn errors.Wrapf(err, \"error writing config update to output\")\n\t}\n\n\treturn nil\n}\n","sourceCodeStart":212,"sourceCodeEnd":235,"githubUrl":"https://github.com/hyperledger/fabric/blob/2736b63f8fd5932511d56fe68b7039d15977f7f6/cmd/configtxlator/main.go#L212-L235","documentation":"After successfully marshaling the computed ConfigUpdate, computeUpdt writes the bytes to the user-specified output file. If that write fails (disk error, bad path, permissions), this wrapped error is returned. It indicates an I/O problem with the output destination, not a config computation problem.","triggerScenarios":"Running 'configtxlator compute-update --output <path>' where the path is in a non-existent directory, is not writable, is a directory itself, or the disk is full.","commonSituations":"Typo in --output path; read-only filesystem or container; output path pointing at a directory; no permission to write in the target dir; disk quota exceeded in CI.","solutions":["Check the wrapped OS error: create the output directory if missing (e.g. mkdir -p).","Verify write permissions on the output location for the user running configtxlator.","If output is a directory, supply a file path instead.","Check disk space/quota (df -h) if in CI or a container."],"exampleFix":"// before\nconfigtxlator compute-update --original cfg.pb --updated upd.pb --channel myc --output /nonexistent/out.pb\n// after\nmkdir -p /tmp/config && configtxlator compute-update --original cfg.pb --updated upd.pb --channel myc --output /tmp/config/out.pb","handlingStrategy":"validation","validationCode":"outPath := \"/tmp/config/out.pb\"\nif err := os.MkdirAll(filepath.Dir(outPath), 0o755); err != nil {\n    log.Fatal(err)\n}\nif info, err := os.Stat(outPath); err == nil && info.IsDir() {\n    log.Fatalf(\"%s is a directory, need a file path\", outPath)\n}","typeGuard":null,"tryCatchPattern":null,"preventionTips":["Always mkdir the output directory before running configtxlator","Use absolute file paths, not directories, for --output","Check available disk space in CI before writing artifacts","Avoid read-only mounts as output targets"],"tags":["io","filesystem","configtxlator"],"backgroundTag":"file-write-failed","analyzedSha":"2736b63f8fd5932511d56fe68b7039d15977f7f6","analyzedAt":"2026-09-04T08:52:36.465Z","contentChangedAt":"2026-09-04T08:52:36.465Z","schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}