{"record":{"id":"f7a648e1abe3e0fd","repo":"hashicorp/packer","slug":"error-initializing-post-processor-s-s","errorCode":null,"errorMessage":"error initializing post-processor '%s': %s","messagePattern":"error initializing post-processor '(.+?)': (.+?)","errorType":"error_code","errorClass":null,"httpStatus":null,"severity":"error","filePath":"packer/core.go","lineNumber":554,"sourceCode":"\t\t\t\terr := fmt.Errorf(\n\t\t\t\t\t\"The post-processor %s is unknown by Packer, and is likely part of a plugin that is not installed.\\n\"+\n\t\t\t\t\t\t\"You may find the needed plugin along with installation instructions documented on the Packer integrations page.\\n\\n\"+\n\t\t\t\t\t\t\"https://developer.hashicorp.com/packer/integrations?filter=%s\",\n\t\t\t\t\trawP.Type,\n\t\t\t\t\tstrings.Split(rawP.Type, \"-\")[0],\n\t\t\t\t)\n\n\t\t\t\tif sugg := didyoumean.NameSuggestion(rawP.Type, c.components.PluginConfig.PostProcessors.List()); sugg != \"\" {\n\t\t\t\t\terr = fmt.Errorf(\"Did you mean to use %q?\", sugg)\n\t\t\t\t}\n\n\t\t\t\treturn nil, err\n\t\t\t}\n\n\t\t\t// Get the post-processor\n\t\t\tpostProcessor, err := c.components.PluginConfig.PostProcessors.Start(rawP.Type)\n\t\t\tif err != nil {\n\t\t\t\treturn nil, fmt.Errorf(\n\t\t\t\t\t\"error initializing post-processor '%s': %s\",\n\t\t\t\t\trawP.Type, err)\n\t\t\t}\n\t\t\tif postProcessor == nil {\n\t\t\t\treturn nil, fmt.Errorf(\n\t\t\t\t\t\"post-processor type not found: %s\", rawP.Type)\n\t\t\t}\n\n\t\t\tcurrent = append(current, CoreBuildPostProcessor{\n\t\t\t\tPostProcessor:     postProcessor,\n\t\t\t\tPType:             rawP.Type,\n\t\t\t\tPName:             rawP.Name,\n\t\t\t\tconfig:            rawP.Config,\n\t\t\t\tKeepInputArtifact: rawP.KeepInputArtifact,\n\t\t\t})\n\t\t}\n\n\t\t// If we have no post-processors in this chain, just continue.","sourceCodeStart":536,"sourceCodeEnd":572,"githubUrl":"https://github.com/hashicorp/packer/blob/eb36e3c3e48a036f3e8cc94087636ee72e1303c9/packer/core.go#L536-L572","documentation":"Thrown by Core.Build at packer/core.go:554 when PluginConfig.PostProcessors.Start(rawP.Type) returns a non-nil error while starting the post-processor plugin. The plugin was found and known, but instantiating it failed (e.g. binary failed to launch, plugin crashed on startup, or the plugin returned a discovery/init error).","triggerScenarios":"Core.Build calls PostProcessors.Start(type) and Start returns err != nil after the type passed the Has() check.","commonSituations":"Plugin binary is incompatible (built against a mismatched SDK/protocol version); plugin binary exists but fails to execute (bad arch, missing permissions); plugin panics during Configure; corrupted download from `packer init`.","solutions":["Reinstall the plugin with `packer plugins install <source>` or delete ~/.packer.d/plugins and re-run `packer init`","Check `packer version` against the plugin's documented Packer compatibility and upgrade one side","Run with PACKER_LOG=1 to see the underlying plugin start error and fix per its message","Verify the plugin binary is executable and matches your OS/architecture"],"exampleFix":"# before: stale/corrupt plugin binary\nrm -rf ~/.packer.d/plugins/github.com/hashicorp/<plugin>\npacker init .","handlingStrategy":"retry","validationCode":"# confirm binary executes and matches arch\nfile ~/.packer.d/plugins/**/<plugin>\nPACKER_LOG=1 packer validate .","typeGuard":null,"tryCatchPattern":"if strings.Contains(err.Error(), \"error initializing post-processor\") {\n    // reinstall plugin, then retry once\n    exec.Command(\"packer\", \"init\", \".\").Run()\n}\n","preventionTips":["Pin plugin versions in required_plugins to avoid protocol/SDK mismatches","Keep Packer and plugins upgraded together","Re-run `packer init` after Packer major upgrades","Inspect PACKER_LOG=1 output when a plugin fails to start"],"tags":["packer","plugin","post-processor","initialization"],"backgroundTag":"plugin-initialization-failed","analyzedSha":"eb36e3c3e48a036f3e8cc94087636ee72e1303c9","analyzedAt":"2026-09-05T13:20:43.127Z","contentChangedAt":"2026-09-05T13:20:43.127Z","schemaVersion":2},"datasetVersion":"2026-09-12T17:17:11.597Z"}