Foundation import file not found

[Peter Wiehe]

Hi all,

I'm new to Objective-C and GNUStep. I am using xubuntu 18.04 GNU/Linux.

I installed GNUStep with "sudo apt-get install gnustep gnustep devel".

I'm trying to compile a simple Hello World Objc program which imports 
Foundation/Foundation.h.

The first line of that program is "#import <Foundation/Foundation.h>".

I compile with "gcc -x objective.c hello.m -o hello".

But there comes an error message because the compiler can't find the 
Foundation file.

What is wrong?

Kind regards

Peter