siyuan-note/siyuan · error

name is empty

Error message

name is empty

What it means

validateEnvironmentName is part of stdio MCP server environment validation: every InheritEnv and Env key must be a non-empty string that contains no '=' or NUL byte, because these characters cannot appear in a NAME=VALUE environment entry. An empty key triggers this bare "name is empty" error before the subprocess starts.

Solutions

1. Remove empty-string entries from InheritEnv and delete any "" key from the Env map
2. Provide the actual variable name, e.g. {"Env": {"MY_VAR": "value"}}
3. Re-save the MCP server configuration through the UI so the environment fields are rebuilt correctly
4. Add a pre-save check that every env name is non-empty and free of '=' and NUL

Example fix

// before
"inheritEnv": ["PATH", ""]
// after
"inheritEnv": ["PATH"]

func validEnvNames(names []string) bool {
    for _, n := range names {
        if n == "" || strings.ContainsAny(n, "=\x00") {
            return false
        }
    }
    return true
}

null

if err := validateMCPServerEnvironment(server, runtime.GOOS); err != nil {
    return fmt.Errorf("environment config invalid for server %q: %w", server.Name, err)
}

When it happens

Trigger: validateMCPServerEnvironment iterates server.InheritEnv or server.Env and passes an empty-string name to validateEnvironmentName — e.g. an InheritEnv array containing "" or an Env JSON object with an empty key.

Common situations: Malformed config JSON with {"": "value"}, an InheritEnv list with a trailing empty entry, programmatic config generation that left a name unset, or hand-editing that removed the variable name but kept the value.

Understand the failure class

Background: "must not be empty", "cannot be empty" — required-field validation errors across open-source libraries — this error's family across 41 libraries.

Related errors

• attr must be a string or null (got %T)
• each key must be an object
• each key requires name and type
• environment
• field [file] or [url] must not be empty

AI-assisted analysis of siyuan-note/siyuan@9f775e8a12 (2026-09-19). Data as JSON: /api/errors/b706b896d3049499. Report an issue: GitHub.

Appendix: source

Thrown at kernel/mcp/client/mcp.go:538

	sort.Strings(keys)
	ret := make([]string, 0, len(keys))
	for _, key := range keys {
		entry := entries[key]
		ret = append(ret, entry.name+"="+entry.value)
	}
	return ret, nil
}

func environmentKey(name, goos string) string {
	if goos == "windows" {
		return strings.ToUpper(name)
	}
	return name
}

func validateEnvironmentName(name string) error {
	if name == "" {
		return errors.New("name is empty")
	}
	if strings.ContainsAny(name, "=\x00") {
		return fmt.Errorf("invalid name %q", name)
	}
	return nil
}

func validateMCPServerEnvironment(server conf.MCPServer, goos string) error {
	inherited := map[string]bool{}
	for _, name := range server.InheritEnv {
		if err := validateEnvironmentName(name); err != nil {
			return err
		}
		key := environmentKey(name, goos)
		if inherited[key] {
			return fmt.Errorf("duplicate inherited variable %q", name)
		}
		inherited[key] = true

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