{"record":{"id":"bd6ac4e90cd8884b","repo":"hyperledger/fabric","slug":"error-computing-config-update","errorCode":null,"errorMessage":"error computing config update","messagePattern":"error computing config update","errorType":"console","errorClass":null,"httpStatus":null,"severity":"error","filePath":"cmd/configtxlator/main.go","lineNumber":218,"sourceCode":"\terr = proto.Unmarshal(origIn, origConf)\n\tif err != nil {\n\t\treturn errors.Wrapf(err, \"error unmarshalling original config\")\n\t}\n\n\tupdtIn, err := io.ReadAll(updated)\n\tif err != nil {\n\t\treturn errors.Wrapf(err, \"error reading updated config\")\n\t}\n\n\tupdtConf := &cb.Config{}\n\terr = proto.Unmarshal(updtIn, updtConf)\n\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":200,"sourceCodeEnd":235,"githubUrl":"https://github.com/hyperledger/fabric/blob/2736b63f8fd5932511d56fe68b7039d15977f7f6/cmd/configtxlator/main.go#L200-L235","documentation":"update.Compute(origConf, updtConf) computes the delta between the two channel configs and failed; wrapped as \"error computing config update\". Compute returns errors when the two configs are structurally incompatible for diffing — most notably different channel IDs, or invalid/missing groups and policies.","triggerScenarios":"Original and updated configs belong to different channels, a config group was removed entirely where removal is unsupported, policy references are broken, or the configs are empty/invalid after unmarshal.","commonSituations":"Comparing configs from different channels by mistake, building the updated config on a mismatched base (out-of-sync orderer state), or hand-editing JSON so group/version structure became invalid.","solutions":["Verify both configs are for the same channel ID (compare the channel_id in decoded JSON)","Regenerate the updated config from the actual current config of the target channel","Undo invalid manual edits (e.g. removed required groups/policies) and re-diff","Pull a fresh config from the ordering service and redo decode → edit → encode → compute-update"],"exampleFix":"// before\nconfigtxlator compute-update --channel channelA --original channelB_config.pb --updated updt.pb ...\n// after\nconfigtxlator compute-update --channel channelA --original channelA_current.pb --updated channelA_edited.pb ...","handlingStrategy":"try-catch","validationCode":"// decode both and compare channel IDs before compute-update\ngrep -o '\"channel_id\":\"[^\"]*\"' config.json updated.json | sort -u | wc -l | grep -q '^1$' || { echo \"channel mismatch\"; exit 1; }","typeGuard":null,"tryCatchPattern":"out, err := cmd.CombinedOutput()\nif err != nil && strings.Contains(string(out), \"error computing config update\") {\n    // refetch current config from orderer and rebuild the diff\n}","preventionTips":["Ensure both configs come from the same channel","Always base edits on the freshest config fetched from the orderer","Avoid deleting required groups/policies in manual edits","Automate the decode→edit→encode→compute-update pipeline"],"tags":["config-update","configtxlator","fabric","diff"],"backgroundTag":"config-compute-update-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"}