[The DJ]

I'm experiencing the followig type of problems with cc and ProjectBuilder.

Code:
[thedj:~/Download/findutils-4.1] thedj% make
for subdir in lib find xargs locate doc testsuite; do \
  echo making all in $subdir ; \
  (cd $subdir; make all); \
done
making all in lib
cc -c -DHAVE_CONFIG_H -I.. -I.  -g -O regex.c
regex.c:34: header file 'sys/types.h' not found
regex.c:72: header file 'strings.h' not found
regex.c:130: header file 'ctype.h' not found
make[1]: *** [regex.o] Error 1
making all in find
cc -c -DHAVE_CONFIG_H -I.. -I../lib  -g -O find.c
find.c:26: header file 'sys/types.h' not found
find.c:27: header file 'sys/stat.h' not found
find.c:28: header file 'stdio.h' not found
find.c:32: header file 'sys/file.h' not found
defs.h:21: header file 'strings.h' not found
defs.h:30: header file 'errno.h' not found
defs.h:43: header file 'time.h' not found
defs.h:139: undefined type, found `FILE'
defs.h:176: undefined type, found `time_t'
defs.h:179: undefined type, found `FILE'
defs.h:204: undefined type, found `FILE'
defs.h:317: undefined type, found `time_t'
find.c:78: undefined type, found `time_t'
find.c:150: illegal expression, found `)'
find.c:150: illegal function call, found `0'
make[1]: *** [find.o] Error 1
making all in xargs
cc -c -DHAVE_CONFIG_H -I.. -I../lib  -g -O xargs.c
xargs.c:30: header file 'ctype.h' not found
xargs.c:48: header file 'sys/types.h' not found
xargs.c:49: header file 'stdio.h' not found
xargs.c:50: header file 'errno.h' not found
xargs.c:59: header file 'strings.h' not found
xargs.c:67: header file 'sys/param.h' not found
xargs.c:78: header file 'signal.h' not found
../lib/wait.h:18: header file 'sys/types.h' not found
xargs.c:249: undefined type, found `FILE'
xargs.c:715: undefined type, found `FILE'
xargs.c:906: undefined type, found `FILE'
make[1]: *** [xargs.o] Error 1
making all in locate
cc -c -DHAVE_CONFIG_H -I.. -I../lib -DLOCATE_DB=\"/usr/local/var/locatedb\"  -g -O locate.c
locate.c:51: header file 'stdio.h' not found
locate.c:52: header file 'sys/types.h' not found
locate.c:53: header file 'sys/stat.h' not found
locate.c:54: header file 'time.h' not found
locate.c:59: header file 'assert.h' not found
locate.c:64: header file 'strings.h' not found
locate.c:101: undefined type, found `FILE'
locate.c:169: undefined type, found `FILE'
locate.c:204: undefined type, found `time_t'
locate.c:341: undefined type, found `FILE'
make[1]: *** [locate.o] Error 1
making all in doc
make[1]: Nothing to be done for `all'.
making all in testsuite
make[1]: Nothing to be done for `all'.

I guess the path to the headerfiles etc. in my frameworks are lost. (Cause the files are there)
I'm totally new at this cc and c in general.
Can someone tell me how i can fix this? I tried reinstallig the package, but that didn't solve it. I tried removing the Developer directory and installing again and that didn't work either.
Can someone tell me where those paths are being stored and which ones the should be?

I'd rather not have to install the whole OS from the bottom up cause that really is a pain.

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