http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48910
--- Comment #1 from joseph at codesourcery dot com <joseph at codesourcery dot com> 2011-05-06 10:59:15 UTC --- On Fri, 6 May 2011, Adam_5Wu at Hotmail dot com wrote: > The workaround is to stop inserting "." in the system include search path > chain. > > In file gcc-4.6.0/gcc/incpath.c, replace > path = xstrdup ("."); > with > continue; But that code is processing an environment variable, and it's absolutely standard that empty elements in PATH-like environment variables are processed as ".". What environment variable is set to contain an empty element, and how did it get set like that? The problem is that the environment variable is set, and the fix must be to stop it from being set. If the variable was not set by something in GCC, then this is not a GCC bug but a problem with your build environment.