Error building on macOS 10.14.1 and Xcode 10.1

[mario-grgic]

I configure the build like this

./configure --with-features=huge --enable-rubyinterp --enable-pythoninterp --enable-python3interp --enable-perlinterp --enable-cscope

and get the following error:

gcc -c -I. -g  -DPERL_DARWIN -fno-strict-aliasing -fstack-protector  -iwithsysroot /System/Library/Perl/5.18/darwin-thread-multi-2level/CORE  -Iproto -DHAVE_CONFIG_H -DFEAT_GUI_MACVIM -Wall -Wno-unknown-pragmas -pipe  -DMACOS_X -DMACOS_X_DARWIN  -g -O2 -U_FORTIFY_SOURCE -D_FORTIFY_SOURCE=1        -o objects/if_perl.o auto/if_perl.c
if_perl.xs:57:10: fatal error: 'EXTERN.h' file not found
#include <EXTERN.h>
         ^~~~~~~~~~
1 error generated.
make: *** [objects/if_perl.o] Error 1
make: *** Waiting for unfinished jobs....
$ 

[mario-grgic]

This error is due to stale /usr/include directory left from previous Xcode installations. Removing /usr/include and then running /Library/Developer/CommandLineTools/Packages/macOS_SDK_headers_for_macOS_10.14.pkg to install it again fixes this problem.

I guess overarching problem is that MacVim build should not be relying in /usr/include being present, and use the compiler toolchain includes from /Application/Xcode.app instead.