option('tls_library', type: 'combo', choices: ['openssl', 'wolfssl', 'aws-lc'],
  description: 'Which TLS library to use')
option('WOLFSSL_TRUST_FILE', type: 'string', value: '/etc/ssl/cert.pem', 
  description: 'Where to look for the trust anchors certificate bundle file')
option('krb5-gssapi', type: 'feature',
  description: 'Support GSSAPI via MIT Kerberos5 or Heimdal')
