Self-signed CA certificate with Flutter iOS (workaround solution)

# Keep running in background. This is a dummy TLS server, not a full gRPC server.
./server.sh

# Test connectivity
curl --cacert assets/pki/ca/ca.crt 'https://localhost:13100/'

# Build protobuf
./build-proto.sh

# Start iOS simulator and run the app
flutter run

If the TLS certificate is accepted, you should see this log entry (because of the dummy gRPC server not sending any responses):

[VERBOSE-2:ui_dart_state.cc(209)] Unhandled Exception: gRPC Error (code: 4, codeName: DEADLINE_EXCEEDED, message: Deadline exceeded, details: null, rawResponse: null, trailers: {})

On TLS failure, you would see something like this:

[VERBOSE-2:ui_dart_state.cc(209)] Unhandled Exception: gRPC Error (code: 14, codeName: UNAVAILABLE, message: Error connecting: HandshakeException: Handshake error in client (OS Error:
    CERTIFICATE_VERIFY_FAILED: application verification failure(handshake.cc:359)), details: null, rawResponse: null, trailers: {})