Install gobjc-5-alpha-linux-gnu by entering the following commands in the terminal:
sudo apt update sudo apt install gobjc-5-alpha-linux-gnu
Description:
GNU Objective-C compiler
This is the GNU Objective-C compiler, which compiles Objective-C on platforms supported by the gcc compiler. It uses the gcc backend to generate optimized code.
Homepage: http://gcc.gnu.org/
Version: 5.5.0-12ubuntu1cross1
Section: universe/devel