{"record":{"id":"e72529e5e4eb54c4","repo":"GoogleContainerTools/skaffold","slug":"extracting-sync-rules-from-labels-for-q-w","errorCode":null,"errorMessage":"extracting sync rules from labels for %q: %w","messagePattern":"extracting sync rules from labels for %q: %w","errorType":"exception","errorClass":null,"httpStatus":null,"severity":"error","filePath":"pkg/skaffold/sync/sync.go","lineNumber":197,"sourceCode":"\tcase a.KanikoArtifact != nil:\n\t\treturn docker.SyncMap(ctx, a.Workspace, a.KanikoArtifact.DockerfilePath, a.KanikoArtifact.BuildArgs, cfg)\n\n\tdefault:\n\t\treturn nil, build.ErrSyncMapNotSupported{}\n\t}\n}\n\nfunc autoSyncItem(ctx context.Context, a *latest.Artifact, tag string, e filemon.Events, cfg docker.Config) (*Item, error) {\n\tswitch {\n\tcase a.BuildpackArtifact != nil:\n\t\tlabels, err := Labels(ctx, tag, cfg)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"retrieving labels for %q: %w\", tag, err)\n\t\t}\n\n\t\trules, err := buildpacks.SyncRules(labels)\n\t\tif err != nil {\n\t\t\treturn nil, fmt.Errorf(\"extracting sync rules from labels for %q: %w\", tag, err)\n\t\t}\n\n\t\treturn syncItem(ctx, a, tag, e, rules, cfg)\n\n\tcase a.JibArtifact != nil:\n\t\ttoCopy, toDelete, err := jib.GetSyncDiff(ctx, a.Workspace, a.JibArtifact, e)\n\t\tif err != nil {\n\t\t\treturn nil, err\n\t\t}\n\t\tif toCopy == nil && toDelete == nil {\n\t\t\t// do a rebuild\n\t\t\treturn nil, nil\n\t\t}\n\t\treturn &Item{Image: tag, Artifact: a, Copy: toCopy, Delete: toDelete}, nil\n\n\tdefault:\n\t\t// TODO: this error does appear a little late in the build, perhaps it could surface at first run, rather than first sync?\n\t\treturn nil, fmt.Errorf(\"Sync: Auto is not supported by the build of %s\", a.ImageName)","sourceCodeStart":179,"sourceCodeEnd":215,"githubUrl":"https://github.com/GoogleContainerTools/skaffold/blob/a1189de023efc32d4b8e11f395acc678aa555011/pkg/skaffold/sync/sync.go#L179-L215","documentation":"For buildpack artifacts, autoSyncItem extracts container filesystem sync rules (which files to copy/delete) from the image's buildpack metadata labels. If buildpacks.SyncRules cannot parse those labels (missing or malformed lifecycle metadata), Skaffold returns this wrapped error.","triggerScenarios":"The image referenced by `tag` lacks well-formed `io.buildpacks.*` label JSON — e.g. built by a non-CNB builder, built with an unsupported lifecycle version, or the labels were stripped by a registry/rewrite step.","commonSituations":"Pointing skaffold at an image built outside pack (plain docker build) but configured as a buildpack artifact; migrating to a new pack/CLI version with changed label schema; using a builder image whose lifecycle metadata is outdated.","solutions":["Rebuild the image with `pack build` using a current CNB-compliant builder so lifecycle labels are present","Confirm the artifact really is a buildpack build in skaffold.yaml; if not, switch the build type or use explicit `sync.manual` rules instead of auto sync","Inspect labels with `docker image inspect <tag> --format '{{json .Config.Labels}}'` and verify io.buildpacks lifecycle JSON parses"],"exampleFix":"// before (docker-built image but buildpack artifact config)\nbuild:\n  artifacts:\n    - image: app\n      buildpacks: {builder: \"\"}\n// after\nbuild:\n  artifacts:\n    - image: app\n      buildpacks:\n        builder: paketobuildpacks/builder:base","handlingStrategy":"fallback","validationCode":"labels, err := sync.Labels(ctx, tag, cfg)\nif err != nil { return err }\nif _, err := buildpacks.SyncRules(labels); err != nil { return err }","typeGuard":null,"tryCatchPattern":"item, err := sync.NewItem(ctx, a, tag, e, cfg, builds)\nif err != nil { return err }","preventionTips":["Rebuild buildpack images with a current pack builder before dev sessions"],"tags":["skaffold","sync","buildpacks","labels","cnb"],"backgroundTag":"invalid-buildpack-metadata","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"}