in my tests gcc 4.1.0-RC{1,2} install headers into a root (/) include directory:
# cut -f 2- fl_wrapper.wlog | grep '^\/include\/' | cut -d / -f 1-4 | uniq /include/c++ /include/c++/gcj /include/c++/gnu /include/c++/java /include/c++/javax /include/c++/org /include/c++/java /include/c++/gnu /include/c++/gcj /include/c++/gnu /include/c++/java /include/c++/javax /include/c++/org /include/c++/java /include/c++/gnu configure arguments have been: --prefix=/usr --bindir=/usr/bin --sbindir=/usr/sbin --libdir=/usr/lib64 \ --datadir=/usr/share --includedir=/usr/include --infodir=/usr/info \ --mandir=/usr/man --sysconfdir=/etc --localstatedir=/var \ --build=x86_64-t2-linux-gnu --host=x86_64-t2-linux-gnu \ --enable-__cxa_atexit --disable-checking --enable-multilib \ --with-gnu-as --with-gnu-ld --enable-threads=posix \ --enable-version-specific-runtime-libs --enable-libgcj --enable-shared there's no definition of libsubdir in libjava Makefile*. Explicit handing --with-gxx-include-dir=/usr/include does work around the issue. Mark Mitchell said the Java Makefile.am incorrect; users of TL_AC_GXX_INCLUDE_DIR must define libsubdir. -- Summary: gcc-4.1.0-RC{1,2} install headers into a top-level (root) /include Product: gcc Version: 4.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: other AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: rene at exactcode dot de http://gcc.gnu.org/bugzilla/show_bug.cgi?id=26522