gohugoio/hugo · error

unsupported drop type: %q

Error message

unsupported drop type: %q

What it means

The `drop` option tells esbuild to strip constructs from the output. Hugo supports exactly one of "console" (remove console.* calls) or "debugger" (remove debugger statements), or empty for none; any other value produces this error. Note esbuild itself allows both simultaneously, but Hugo's option is a single string.

Source

Thrown at internal/js/esbuild/options.go:397

	default:
		err = fmt.Errorf("unsupported platform type: %q", opts.Platform)
		return
	}

	var defines map[string]string
	if opts.Defines != nil {
		defines = hmaps.ToStringMapString(opts.Defines)
	}

	var drop api.Drop
	switch opts.Drop {
	case "":
	case "console":
		drop = api.DropConsole
	case "debugger":
		drop = api.DropDebugger
	default:
		err = fmt.Errorf("unsupported drop type: %q", opts.Drop)
	}

	// By default we only need to specify outDir and no outFile
	outDir := opts.OutDir
	outFile := ""
	var sourceMap api.SourceMap
	switch opts.SourceMap {
	case "inline":
		sourceMap = api.SourceMapInline
	case "external":
		sourceMap = api.SourceMapExternal
	case "linked":
		sourceMap = api.SourceMapLinked
	case "", "none":
		sourceMap = api.SourceMapNone
	default:
		err = fmt.Errorf("unsupported sourcemap type: %q", opts.SourceMap)
		return

View on GitHub (pinned to 8a468df065)

Solutions

1. Set drop to exactly "console" or "debugger".
2. If you need both dropped, drop "console" via this option and rely on minification/manual removal for debugger statements, or open a feature request — Hugo currently accepts only one.
3. Remove the option if you don't need stripping.

Example fix

{{/* before */}}
{{ $js := resources.Get "main.js" | js.Build (dict "drop" "console,debugger") }}
{{/* after */}}
{{ $js := resources.Get "main.js" | js.Build (dict "drop" "console") }}

validDrop := map[string]bool{"": true, "console": true, "debugger": true}
if !validDrop[opts.Drop] {
    return fmt.Errorf("invalid drop option %q; must be console or debugger", opts.Drop)
}

When it happens

Trigger: Passing `dict "drop" "console,debugger"`, "logs", or an array to js.Build/js.Batch; any value other than "", "console", "debugger".

Common situations: Trying to drop both console and debugger in one option (esbuild CLI style `--drop:console --drop:debugger` doesn't map to Hugo's single-string option); typos like "consoles" or "console.log".

Related errors

• inject: absolute paths not supported, must be relative to /a
• invalid engine version: %q
• unsupported target: %v
• invalid loader: %q
• unsupported script output format: %q

AI-assisted analysis of gohugoio/hugo@8a468df065 (2026-07-31). Data as JSON: /data/errors/c9c66d8977a8d326.json. Report an issue: GitHub.