Problem: 

After updating to Mojave, terminal cannot locate /System/Library/Frameworks. When I want to compile an objective-c file which imports CoreFoundation or other frameworks, using the command:

clang -framework CoreFoundation test.m -o test

It prompted the error:

fatal error

<CoreFoundation/CoreFoundation.h> not found

 

Solution:

tap brew doctor  on terminal. It suggests run a Mac prefix installer  which  is located on

/Library/Developer/CommandLineTools

or try:

xcode-select –install

to update CommandLineTools.