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