What causes "parsing template: %w" in GoogleContainerTools/skaffold?

Fix the Go template syntax in skaffold.yaml (every {{ }} must be closed and use valid template constructs)

parsing template: %w

Error message

parsing template: %w

What it means

NewEnvTemplateTagger wraps the envTemplateTagger construction; the template string from skaffold.yaml is parsed with util.ParseEnvTemplate (Go text/template). If the template has invalid syntax (unclosed actions, bad pipes, stray braces), construction fails and the parse error is wrapped with 'parsing template:'.

Source

Thrown at pkg/skaffold/tag/env_template.go:38

	"context"
	"fmt"
	"strings"
	"text/template"

	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/schema/latest"
	"github.com/GoogleContainerTools/skaffold/v2/pkg/skaffold/util"
)

// envTemplateTagger implements Tagger
type envTemplateTagger struct {
	Template *template.Template
}

// NewEnvTemplateTagger creates a new envTemplateTagger
func NewEnvTemplateTagger(t string) (Tagger, error) {
	tmpl, err := util.ParseEnvTemplate(t)
	if err != nil {
		return nil, fmt.Errorf("parsing template: %w", err)
	}

	return &envTemplateTagger{
		Template: tmpl,
	}, nil
}

// GenerateTag generates a tag from a template referencing environment variables.
func (t *envTemplateTagger) GenerateTag(ctx context.Context, image latest.Artifact) (string, error) {
	// The method with missingkey=invalid option does not fail if the referenced variable does not exist in the map.
	// It will be replaced by <no value> if no other Go template method handles the missing key.
	// This gives us an opportunity to handle missing keys with other Go template methods. For example, the default method
	// can be used to set a default value for a missing key. The evaluation of {{default "bar" .FOO}} should be "bar" and
	// tagging should succeed if the environment variable .FOO does not exist.
	tag, err := util.ExecuteEnvTemplate(t.Template.Option("missingkey=invalid"), map[string]string{
		"IMAGE_NAME": image.ImageName,
	})
	if err != nil {

View on GitHub (pinned to a1189de023)

Solutions

Fix the Go template syntax in skaffold.yaml (every {{ }} must be closed and use valid template constructs)
Test the template standalone with text/template in Go or `go run` to see the exact parse position
Use '{{.FOO}}' env-template form (no custom funcs) — unsupported functions also fail parsing
Validate skaffold.yaml with `skaffold config` / `skaffold build --dry-run` before running builds

Example fix

// before
NewEnvTemplateTagger("{{ .TAG }}-{{ DATE }")
// after
NewEnvTemplateTagger("{{ .TAG }}-{{ .DATE }}")

Defensive patterns

Strategy: validation

Validate before calling

if _, err := template.New("t").Parse(cfg.Template); err != nil {
    return fmt.Errorf("invalid env template %q: %w", cfg.Template, err)
}

Try / catch

tagger, err := tag.NewEnvTemplateTagger(tmpl)
if err != nil {
    return fmt.Errorf("configuring env template tagger: %w", err)
}

Prevention

Use valid Go text/template syntax ({{ .VAR }}), not shell $VAR
Close every {{ with }}
Validate templates in a unit test or with a quick Go snippet
Use IDE schema validation for skaffold.yaml

When it happens

Trigger: Calling NewEnvTemplateTagger("{{ .IMAGE }}") or configuring tagger.env_Template.template_Template with malformed Go template syntax such as '{{ FOO' (missing closing braces) or '{{ .FOO | badFunc }}'.

Common situations: Hand-editing skaffold.yaml and leaving an unclosed {{ or using shell-style $VAR syntax instead of Go template syntax; quoting issues in YAML mangling the template string.

Related errors

AI-assisted analysis of GoogleContainerTools/skaffold@a1189de023 (2026-09-05). Data as JSON: /api/errors/1ccb60415b9336e4. Report an issue: GitHub.