-I include path troubles

[Joe Anthony]

Hi,

I just upgraded gcc from 2.95 to 3.2.2 and then to 3.3.3. I saw this
problem with both 3.2.2 and 3.3.3. I'm running autoconf 2.59, glibc
2.2.5, kernel 2.6.0.

I've been having problems compiling/configuring a few programs
(gimp,xchat, and a number of gnome libraries) after upgrading gcc. The
problem seems to be an extra -I option with no include path provided,
breaks the following -I</path/to/include>, with an "ignoring nonexistent
directory" warning message.

I'm not really sure what the problem really is, Gcc, autoconf or the
individual configure scripts? Is this the correct behavior of an empty
-I option? 
 
Ex:
test.c:
#include <glib.h>
int main(int argc, char **argv) {
   ;
}

gcc -I -I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include  -v -o test
test.c

Reading specs from /usr/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/specs
Configured with: ../gcc-3.3.3/configure --prefix=/usr
Thread model: posix
gcc version 3.3.3
 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/cc1 -quiet -v -I
-I/usr/include/glib-2.0 -I/usr/lib/glib-2.0/include -D__GNUC__=3
-D__GNUC_MINOR__=3 -D__GNUC_PATCHLEVEL__=3 test.c -quiet -dumpbase
test.c -auxbase test -version -o /tmp/cc3FuuPj.s
ignoring nonexistent directory "-I/usr/include/glib-2.0"
GNU C version 3.3.3 (i686-pc-linux-gnu)
        compiled by GNU C version 3.2.2.
GGC heuristics: --param ggc-min-expand=51 --param ggc-min-heapsize=40074
#include "..." search starts here:
#include <...> search starts here:
 /usr/lib/glib-2.0/include
 /usr/local/include
 /usr/lib/gcc-lib/i686-pc-linux-gnu/3.3.3/include
 /usr/i686-pc-linux-gnu/include
 /usr/include
End of search list.
test.c:2:18: glib.h: No such file or directory

thanks for any help,
-joe