I'm using my slightly modified version of the first script found in "compiling everything from scratch" article from wiki.gnustep (commented out first make & libobjc2 builds...).
Everything work well untill the script reach: Building GNUstep-Base...
error return missing : ../../Headers/Foundation/NSException.h
If you let the script to run, then AppKit/Appkit.h also is missing
The script uses git to get the gnustep tree but do not try to clone Foundation nor AppKit packages.