Why is $prefix/include not inside cpp searchpath?

[Martin Kahlert <martin dot kahlert at infineon dot com>]

Hi!

I checked out yesterday's gcc version and found that jni.h is not
found any more although it's there:

$ cat c.c
#include <jni.h>

$ ls -l /sw/gcc-3.1/include/jni.h
-rw-r--r--    1 kahlert  titan       54922 Sep 19 11:54

$ gcc -v -E c.c
Reading specs from /sw/gcc-3.1/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
Configured with: ../gcc-3.1/configure --prefix=/sw/gcc-3.1 --enable-languages=c++,f77,java --enable-threads=posix
Thread model: posix
gcc version 3.1 20010919 (experimental)
 /sw/gcc-3.1/lib/gcc-lib/i686-pc-linux-gnu/3.1/cpp0 -lang-c -v -D__GNUC__=3 -D__GNUC_MINOR__=1 -D__GNUC_PATCHLEVEL__=0 -D__ELF__ -Dunix -Dlinux -D__ELF__ -D__unix__ -D__linux__ -D__unix -D__linux -Asystem=posix -D__NO_INLINE__ -D__STDC_HOSTED__=1 -Acpu=i386 -Amachine=i386 -Di386 -D__i386 -D__i386__ -D__tune_i686__ -D__tune_pentiumpro__ c.c
GNU CPP version 3.1 20010919 (experimental) (cpplib) (i386 Linux/ELF)
ignoring nonexistent directory "/sw/gcc-3.1/i686-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
 /usr/local/include
 /sw/gcc-3.1/lib/gcc-lib/i686-pc-linux-gnu/3.1/include
 /usr/include
End of search list.
c.c:1:17: jni.h: No such file or directory
# 1 "c.c"
# 1 "<builtin>"
# 1 "<command line>"
# 1 "c.c"

Did i miss anything here?
PS: gcj -E c.c has the same problem.

-- 
The early bird catches the worm. If you want something else for       
breakfast, get up later.