In reply to Norm.

Hello Norm,

Thanks for the reply and details. In the Stack Overflow post that shows how to install clang-3.8 via MacPorts, I found in the step "[2] User-defined setting CC /opt/local/bin/clang-mp/3.8", I assume it is a typo that supposes to be "/opt/local/bin/clang-mp-3.8".

Regarding the "User-defined setting CC", I am still confused. I don't know where I should input the value "/opt/local/bin/clang-mp-3.8" (see the attached figure, "the macOS Default" is not editable).

Many thanks for your patience,
Mono