Error "Bad configuration option: AuthorizedPrincipalsCommand" when running the deploy script

Symptoms

Error "Bad configuration option: AuthorizedPrincipalsCommand" when running the deploy script.

Root Cause

Unsupported OpenSSH version (typically older than OpenSSH 6.9).

Solutions

• Upgrade OpenSSH to a supported version, or
• Configure system with AuthorizedPrincipalsFile instead, see
  Allowing Role-Based Access, or
• Configure system with public key authentication