------- Additional Comments From pinskia at gcc dot gnu dot org 2005-02-09 19:07 ------- I think this related to PR 14435. But reading the docs (there is a section in there which is useful to read): In addition, the prefix is used in an unusual way in finding the directories to search for header files. For each of the standard directories whose name normally begins with /usr/local/lib/gcc (more precisely, with the value of GCC_INCLUDE_DIR), GCC tries replacing that beginning with the specified prefix to produce an alternate directory name. Thus, with -Bfoo/, GCC will search foo/bar where it would normally search /usr/local/lib/bar. These alternate directories are searched first; the standard directories come next.
-- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19856
