fmt.Warnf

The warnf function evaluates the format string, then prints the result to the WARNING log. Hugo prints each unique message once to avoid flooding the log with duplicate warnings.

{{ warnf "The %q shortcode was unable to find %s. See %s" .Name $file .Position }}

Use the warnidf function to allow optional suppression of specific warnings.

To prevent suppression of duplicate messages when using warnf for debugging, make each message unique with the math.Counter function. For example:

{{ range site.RegularPages }}
  {{ .Section | warnf "%#[2]v [%[1]d]" math.Counter }}
{{ end }}