Warning: unable to build self-signed root for signer 'iPhone Developer: ....'

It didn’t work for me. I’m struggling with the exact same problem.

  1. Did you create your certificates on the mac or on windows machine? Mine were created on windows.

  2. Did you copy those certificates to the mac keychain? I copied and tried both login and system but none worked.

  3. Are you signed in to Xcode? I signed in but that didn’t work either.