{"record":{"id":"13d8babe3c74d8d1","repo":"GoogleContainerTools/skaffold","slug":"inferring-syncmap-for-image-q-w","errorCode":null,"errorMessage":"inferring syncmap for image %q: %w","messagePattern":"inferring syncmap for image %q: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/skaffold/sync/sync.go","lineNumber":132,"sourceCode":"\t\tif err != nil {\n\t\t\treturn nil, err\n\t\t}\n\t\treturn &Item{\n\t\t\tImage:    tag,\n\t\t\tArtifact: a,\n\t\t\tCopy:     toCopy,\n\t\t\tDelete:   toDelete,\n\t\t}, nil\n\t}\n\n\t// deleted files are no longer contained in the syncMap, so we need to rebuild\n\tif len(e.Deleted) > 0 {\n\t\treturn nil, nil\n\t}\n\n\tsyncMap, err := SyncMap(ctx, a, cfg)\n\tif err != nil {\n\t\treturn nil, fmt.Errorf(\"inferring syncmap for image %q: %w\", a.ImageName, err)\n\t}\n\n\ttoCopy := make(map[string][]string)\n\tfor _, f := range append(e.Modified, e.Added...) {\n\t\trelPath, err := filepath.Rel(a.Workspace, f)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"finding changed file %s relative to context %q: %w\", f, a.Workspace, err)\n\t\t}\n\n\t\tmatches := false\n\t\tfor _, p := range a.Sync.Infer {\n\t\t\tmatches, err = doublestar.PathMatch(filepath.FromSlash(p), relPath)\n\t\t\tif err != nil {\n\t\t\t\treturn nil, fmt.Errorf(\"pattern error for %q: %w\", relPath, err)\n\t\t\t}\n\t\t\tif matches {\n\t\t\t\tbreak\n\t\t\t}","sourceCodeStart":114,"sourceCodeEnd":150,"githubUrl":"https://github.com/GoogleContainerTools/skaffold/blob/a1189de023efc32d4b8e11f395acc678aa555011/pkg/skaffold/sync/sync.go#L114-L150","documentation":"`inferredSyncItem` wraps failures from `SyncMap`, which infers which container paths can be hot-synced by analyzing the image's history/layers. The error means skaffold could not infer a sync map for the image, so automatic (inferred) file sync cannot proceed for the artifact.","triggerScenarios":"Calling `NewItem` for an artifact using inferred sync where `SyncMap(ctx, a, cfg)` fails — e.g. image metadata is unavailable (image pruned, daemon unreachable), the image history can't be read from the registry due to auth, or the Dockerfile/image format isn't analyzable.","commonSituations":"Images built with builders whose metadata skaffold can't inspect (e.g. non-Docker builds like Jib/Kaniko output without local layers); private registry requiring docker login; base images from private registries breaking history analysis; docker daemon not running.","solutions":["Authenticate to the image's registry (docker login / credential helper) so history can be read.","Verify the image exists locally or remotely and the docker daemon is reachable.","Define explicit manual sync rules (sync: manual: [...]) in skaffold.yaml to bypass inference.","Rebuild the image so fresh, inspectable metadata is available."],"exampleFix":"// before\nbuild:\n  artifacts:\n    - image: app // inference fails on private base image\n// after\nbuild:\n  artifacts:\n    - image: app\n      sync:\n        manual:\n          - src: 'src/**/*.js'\n            dest: /app/src","handlingStrategy":"validation","validationCode":"if _, _, err := exec.Command(\"docker\", \"image\", \"inspect\", tag).CombinedOutput(); err != nil {\n  // image metadata unreadable: inferred sync will fail, configure manual sync rules instead\n  log.Printf(\"image %s not inspectable; manual sync rules required\", tag)\n}","typeGuard":null,"tryCatchPattern":"item, err := sync.NewItem(ctx, artifact, events, builds, cfg)\nif err != nil {\n  if strings.Contains(err.Error(), \"inferring syncmap\") {\n    log.Printf(\"sync inference failed (%v); using manual sync rules or rebuild\", err)\n    return triggerRebuild(artifact)\n  }\n  return err\n}","preventionTips":["docker login to private registries so image history can be read for inference.","Prefer Dockerfile-based builds skaffold can inspect when relying on inferred sync.","Define explicit `sync.manual` rules for artifacts built by non-analyzable builders (Jib, Kaniko).","Ensure the docker daemon is running and the image exists before dev."],"tags":["file-sync","docker","image-metadata","go"],"backgroundTag":"sync-map-inference-failed","analyzedSha":"a1189de023efc32d4b8e11f395acc678aa555011","analyzedAt":"2026-09-05T12:09:27.064Z","contentChangedAt":"2026-09-05T12:09:27.064Z","schemaVersion":2},"datasetVersion":"2026-09-12T17:17:11.597Z"}