lima-vm/lima · error

failed to marshal template %#q again after filling defaults:

Error message

failed to marshal template %#q again after filling defaults: %w

What it means

After successful validation with `--fill`, the command re-marshals the fully-defaulted YAML with `limayaml.Marshal` to print it. This error wraps a failure of that marshal step — not a validation problem, but an inability to serialize the in-memory LimaYAML back to bytes.

Source

Thrown at cmd/limactl/template.go:281

		// Load() will merge the template with override.yaml and default.yaml via FillDefaults().
		// FillDefaults() needs the potential instance directory to validate host templates using {{.Dir}}.
		filePath := filepath.Join(limaDir, tmpl.Name+".yaml")
		y, err := limayaml.Load(ctx, tmpl.Bytes, filePath)
		if err != nil {
			return err
		}
		// If VMType is not specified, we go with the default platform driver.
		if err := driverutil.ResolveVMType(y); err != nil {
			return err
		}
		if err := limayaml.Validate(y, false); err != nil {
			return fmt.Errorf("failed to validate YAML file %#q: %w", arg, err)
		}
		logrus.Infof("%#q: OK", arg)
		if fill {
			b, err := limayaml.Marshal(y, len(args) > 1)
			if err != nil {
				return fmt.Errorf("failed to marshal template %#q again after filling defaults: %w", arg, err)
			}
			fmt.Fprint(cmd.OutOrStdout(), string(b))
		}
	}

	return nil
}

func newTemplateURLCommand() *cobra.Command {
	templateURLCommand := &cobra.Command{
		Use:   "url CUSTOM_URL",
		Short: "Transform custom template URLs to regular file or https URLs",
		Args:  WrapArgsError(cobra.ExactArgs(1)),
		RunE:  templateURLAction,
	}
	return templateURLCommand
}

View on GitHub (pinned to dd909d0973)

Solutions

1. Re-run with a single template argument to rule out multi-doc/indent path issues
2. Inspect the template for exotic values (very large numbers, unusual nested structures) and simplify them
3. Update Lima — if reproducible with stock templates, this indicates a bug; file an issue with the template
4. Skip `--fill` and just validate, if you do not need the defaulted output

Example fix

// before
limactl template validate --fill a.yaml b.yaml
// after
limactl template validate --fill a.yaml   # isolate which input fails marshaling

b, err := limayaml.Marshal(y, multi)
if err != nil {
	return fmt.Errorf("failed to marshal template %q again after filling defaults: %w", arg, err)
}

When it happens

Trigger: Running `limactl template validate --fill <args>` where `limayaml.Marshal(y, len(args) > 1)` returns an error (serialization of the merged/defaulted document failed).

Common situations: Rare; typically only when a custom/monkey-patched type or unusual content in the merged YAML cannot be marshaled by the YAML encoder, or internal bugs in field types.

Related errors

• the YAML is invalid, attempted to save the buffer as %#q but
• the YAML is invalid, saved the buffer as %#q: %w
• invalid parameter %#q, expected NAME=VALUE
• template does not define param %#q
• --verbatim cannot be used with any of --embed, --embed-all,

AI-assisted analysis of lima-vm/lima@dd909d0973 (2026-09-01). Data as JSON: /api/errors/d5ee0b410df5e3a0. Report an issue: GitHub.