fix: use %w instead of %s for error wrapping in fmt.Errorf calls across the codebase

Changes %s to %w in 11 fmt.Errorf calls where the argument is an error
type, enabling proper error chain unwrapping via errors.Is()/errors.As().
This is a Go best practice that ensures callers can inspect the wrapped
error rather than receiving a stringified version.

Includes cleanup of a stray trailing \n in one error format string.

Affected packages:
  pkg/lib/filesystem/unpack/   (4 occurrences in core.go, skill.go, util.go)
  pkg/lib/repo/local/          (2 occurrences in migration.go)
  pkg/cmd/remove/              (2 occurrences in remove.go)
  pkg/cmd/tag/                 (1 occurrence in tag.go)
  pkg/cmd/kitimport/           (1 occurrence in util.go)
  pkg/cmd/dev/                 (1 occurrence in opts.go)

Signed-off-by: Adesh Deshmukh <adeshkd123@gmail.com>

Author: AdeshDeshmukh

pkg/cmd/dev/opts.go

@@ -106,7 +106,7 @@ func (opts *DevStartOptions) complete(ctx context.Context, args []string) error
 	if opts.port == 0 {
 		availPort, err := findAvailablePort()
 		if err != nil {
-			return fmt.Errorf("invalid arguments: %s", err)
+			return fmt.Errorf("invalid arguments: %w", err)
 		}
 		opts.port = availPort
 	}

pkg/cmd/kitimport/util.go

@@ -63,7 +63,7 @@ func generateKitfile(dirContents *kfgen.DirectoryListing, repo string, outDir st
 	}
 	kitfilePath := filepath.Join(outDir, constants.DefaultKitfileName)
 	if err := os.WriteFile(kitfilePath, kitfileBytes, 0644); err != nil {
-		return nil, fmt.Errorf("failed to write Kitfile: %s", err)
+		return nil, fmt.Errorf("failed to write Kitfile: %w", err)
 	}
 	output.Infof("Generated Kitfile:\n\n%s\n", string(kitfileBytes))
 	return kitfile, nil

pkg/cmd/remove/remove.go

@@ -107,7 +107,7 @@ func removeModel(ctx context.Context, opts *removeOptions) error {
 	}
 	desc, err := removeModelRef(ctx, localRepo, opts.modelRef, opts.forceDelete)
 	if err != nil {
-		return fmt.Errorf("failed to remove: %s", err)
+		return fmt.Errorf("failed to remove: %w", err)
 	}
 	displayRef := artifact.FormatRepositoryForDisplay(opts.modelRef.String())
 	output.Infof("Removed %s (digest %s)", displayRef, desc.Digest)
@@ -132,7 +132,7 @@ func removeModelRef(ctx context.Context, localRepo local.LocalRepo, ref *registr
 		if err == errdef.ErrNotFound {
 			return ocispec.DescriptorEmptyJSON, fmt.Errorf("model %s not found", artifact.FormatRepositoryForDisplay(ref.String()))
 		}
-		return ocispec.DescriptorEmptyJSON, fmt.Errorf("error resolving model: %s", err)
+		return ocispec.DescriptorEmptyJSON, fmt.Errorf("error resolving model: %w", err)
 	}
 
 	// If reference passed in is a digest, remove the manifest ignoring any tags the manifest might have

pkg/cmd/tag/tag.go

@@ -38,7 +38,7 @@ func RunTag(ctx context.Context, options *tagOptions) error {
 		if err == errdef.ErrNotFound {
 			return fmt.Errorf("model %s not found", options.sourceRef.String())
 		}
-		return fmt.Errorf("error resolving model: %s", err)
+		return fmt.Errorf("error resolving model: %w", err)
 	}
 	if options.sourceRef.Registry == options.targetRef.Registry && options.sourceRef.Repository == options.targetRef.Repository {
 		err = sourceRepo.Tag(ctx, descriptor, options.targetRef.Reference)

pkg/lib/filesystem/unpack/core.go

@@ -87,7 +87,7 @@ func unpackRecursive(ctx context.Context, opts *UnpackOptions, visitedRefs []str
 	store, err := getStoreForRef(ctx, opts)
 	if err != nil {
 		ref := artifact.FormatRepositoryForDisplay(opts.ModelRef.String())
-		return fmt.Errorf("failed to find reference %s: %s", ref, err)
+		return fmt.Errorf("failed to find reference %s: %w", ref, err)
 	}
 
 	_, manifest, kitfile, err := util.ResolveManifestAndConfig(ctx, store, ref.Reference)

pkg/lib/filesystem/unpack/skill.go

@@ -45,15 +45,15 @@ func unpackSkill(ctx context.Context, opts *UnpackOptions) error {
 	store, err := getStoreForRef(ctx, opts)
 	if err != nil {
 		ref := artifact.FormatRepositoryForDisplay(opts.ModelRef.String())
-		return fmt.Errorf("failed to find reference %s: %s", ref, err)
+		return fmt.Errorf("failed to find reference %s: %w", ref, err)
 	}
 	manifestDesc, err := store.Resolve(ctx, ref.Reference)
 	if err != nil {
 		return fmt.Errorf("failed to resolve reference: %w", err)
 	}
 	manifest, err := util.GetManifest(ctx, store, manifestDesc)
 	if err != nil {
-		return fmt.Errorf("failed to read manifest: %s", err)
+		return fmt.Errorf("failed to read manifest: %w", err)
 	}
 	config, err := util.GetKitfileForManifest(ctx, store, manifest)
 	if err != nil {

pkg/lib/filesystem/unpack/util.go

@@ -131,7 +131,7 @@ func getStoreForRef(ctx context.Context, opts *UnpackOptions) (oras.Target, erro
 	storageHome := constants.StoragePath(opts.ConfigHome)
 	localRepo, err := local.NewLocalRepo(storageHome, opts.ModelRef)
 	if err != nil {
-		return nil, fmt.Errorf("failed to read local storage: %s\n", err)
+		return nil, fmt.Errorf("failed to read local storage: %w", err)
 	}
 
 	if _, err := localRepo.Resolve(ctx, opts.ModelRef.Reference); err == nil {

pkg/lib/repo/local/migration.go

@@ -77,7 +77,7 @@ func MigrateStorage(ctx context.Context, baseStoragePath string) error {
 		// Clean up this repos blobs; we'll clean up the directories later
 		repoDir := localStore.getStorePath()
 		if err := os.RemoveAll(repoDir); err != nil && !errors.Is(err, fs.ErrNotExist) {
-			return fmt.Errorf("failed to clean up directory %s after migration: %s", repoDir, err)
+			return fmt.Errorf("failed to clean up directory %s after migration: %w", repoDir, err)
 		}
 		pb.Increment()
 	}
@@ -90,7 +90,7 @@ func MigrateStorage(ctx context.Context, baseStoragePath string) error {
 		rmDir := filepath.Join(baseStoragePath, baseSubDir)
 		output.Debugf("Removing storage directory %s", rmDir)
 		if err := os.RemoveAll(rmDir); err != nil && !errors.Is(err, fs.ErrNotExist) {
-			return fmt.Errorf("failed to clean up directory %s after migration: %s", rmDir, err)
+			return fmt.Errorf("failed to clean up directory %s after migration: %w", rmDir, err)
 		}
 	}
 	output.Debugf("Migration done!")