conflicting command line arguments, cannot use --cert with o

Error message

conflicting command line arguments, cannot use --cert with other flags

What it means

Error "conflicting command line arguments, cannot use --cert with other flags" thrown in caddyserver/caddy.

Source

Thrown at modules/caddypki/command.go:154

	// Install the cert!
	err = ca.installRoot()
	if err != nil {
		return caddy.ExitCodeFailedStartup, err
	}

	return caddy.ExitCodeSuccess, nil
}

func cmdUntrust(fl caddycmd.Flags) (int, error) {
	certFile := fl.String("cert")
	caID := fl.String("ca")
	addrFlag := fl.String("address")
	configFlag := fl.String("config")
	configAdapterFlag := fl.String("adapter")

	if certFile != "" && (caID != "" || addrFlag != "" || configFlag != "") {
		return caddy.ExitCodeFailedStartup, fmt.Errorf("conflicting command line arguments, cannot use --cert with other flags")
	}

	// If a file was specified, try to uninstall the cert matching that file
	if certFile != "" {
		// Sanity check, make sure cert file exists first
		_, err := os.Stat(certFile)
		if err != nil {
			return caddy.ExitCodeFailedStartup, fmt.Errorf("accessing certificate file: %v", err)
		}

		// Uninstall the file!
		err = truststore.UninstallFile(certFile,
			truststore.WithDebug(),
			truststore.WithFirefox(),
			truststore.WithJava())
		if err != nil {
			return caddy.ExitCodeFailedStartup, fmt.Errorf("failed to uninstall certificate file: %v", err)
		}

View on GitHub (pinned to 50e54ee279)

Solutions

Use --cert by itself; do not combine it with the other flags of the pki command.

When it happens

Trigger: Thrown at modules/caddypki/command.go:154 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of caddyserver/caddy@50e54ee279 (2026-08-15). Data as JSON: /api/errors/ee7d8f086331cde8. Report an issue: GitHub.