{"record":{"id":"397e32c0fa450e00","repo":"hashicorp/nomad","slug":"failed-creating-runner-for-task-q-v","errorCode":null,"errorMessage":"failed creating runner for task %q: %v","messagePattern":"failed creating runner for task %q: (.+?)","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"client/allocrunner/alloc_runner.go","lineNumber":359,"sourceCode":"\t\t\tDeviceStatsReporter: ar.deviceStatsReporter,\n\t\t\tCSIManager:          ar.csiManager,\n\t\t\tDeviceManager:       ar.devicemanager,\n\t\t\tDriverManager:       ar.driverManager,\n\t\t\tServersContactedCh:  ar.serversContactedCh,\n\t\t\tStartConditionMetCh: ar.taskCoordinator.StartConditionForTask(task),\n\t\t\tShutdownDelayCtx:    ar.shutdownDelayCtx,\n\t\t\tServiceRegWrapper:   ar.serviceRegWrapper,\n\t\t\tGetter:              ar.getter,\n\t\t\tWranglers:           ar.wranglers,\n\t\t\tAllocHookResources:  ar.hookResources,\n\t\t\tWIDMgr:              ar.widmgr,\n\t\t\tUsers:               ar.users,\n\t\t}\n\n\t\t// Create, but do not Run, the task runner\n\t\ttr, err := taskrunner.NewTaskRunner(trConfig)\n\t\tif err != nil {\n\t\t\treturn fmt.Errorf(\"failed creating runner for task %q: %v\", task.Name, err)\n\t\t}\n\n\t\tar.tasks[task.Name] = tr\n\t}\n\treturn nil\n}\n\nfunc (ar *allocRunner) WaitCh() <-chan struct{} {\n\treturn ar.waitCh\n}\n\n// Run the AllocRunner. Starts tasks if the alloc is non-terminal and closes\n// WaitCh when it exits. Should be started in a goroutine.\nfunc (ar *allocRunner) Run() {\n\t// Close the wait channel on return\n\tdefer close(ar.waitCh)\n\n\t// Start the task state update handler","sourceCodeStart":341,"sourceCodeEnd":377,"githubUrl":"https://github.com/hashicorp/nomad/blob/482b49bf1aec006f089bcfc7e632d8f6ac303e5e/client/allocrunner/alloc_runner.go#L341-L377","documentation":"initTaskRunners builds a NewTaskRunner config for each task in the group; this error wraps any failure from taskrunner.NewTaskRunner. It means one specific task's runner could not be constructed (driver setup, hook/logmon creation, etc.), aborting alloc initialization.","triggerScenarios":"NewAllocRunner -> initTaskRunners -> taskrunner.NewTaskRunner returns an error for task <name>: invalid task config for the driver, driver initialization failure, bad volume/hook configuration, or invalid user/consul settings in the task block.","commonSituations":"Job specifies a driver not installed/enabled on the client; malformed driver task config (e.g. bad docker image reference or invalid command); task volumes referencing missing host paths; recent Nomad version change introducing stricter validation.","solutions":["Read the wrapped %v cause — it names the actual NewTaskRunner failure (driver, hook, or config)","Validate the task block with `nomad job validate` against the affected client","Install/enable the required driver plugin on the client and restart the agent","Fix the offending task configuration (command, image, volume source, user) and redeploy the job"],"exampleFix":"// before\ntask \"app\" {\n  driver = \"docker\"\n  config { image = \"nginx\" command = \"start\" } // incompatible flags\n}\n// after\nnomad job validate app.nomad  # then fix per validation output\ntask \"app\" {\n  driver = \"docker\"\n  config { image = \"nginx\" }\n}","handlingStrategy":"validation","validationCode":"// Validate the job spec against target clients before deploy\n// CLI: nomad job validate job.nomad\n// API:\n_, _, err := client.Jobs().Validate(nil, job)\nif err != nil { return fmt.Errorf(\"invalid job: %w\", err) }\n// and ensure the driver is available:\nfor _, n := range nodes {\n  if !nodeDrivers[n.Name][\"docker\"] { return fmt.Errorf(\"docker driver missing\") }\n}","typeGuard":null,"tryCatchPattern":"tr, err := taskrunner.NewTaskRunner(trConfig)\nif err != nil {\n  // log err.Error(): names the failing driver/hook; fix config, then re-deploy\n  return fmt.Errorf(\"failed creating runner for task %q: %v\", task.Name, err)\n}","preventionTips":["Run `nomad job validate` before every deployment","Confirm required driver plugins are installed and healthy on clients (`nomad node status -self`)","Keep task config fields valid for the installed Nomad/driver version","Avoid referencing host paths/users that don't exist on target clients"],"tags":["task-runner","driver","configuration","alloc-runner"],"backgroundTag":"task-runner-creation-failed","analyzedSha":"482b49bf1aec006f089bcfc7e632d8f6ac303e5e","analyzedAt":"2026-09-04T07:54:14.808Z","contentChangedAt":"2026-09-04T07:54:14.808Z","schemaVersion":2},"datasetVersion":"2026-09-08T10:18:20.063Z"}