Hi, I do this: ../gcc-4.1-branch/configure --prefix=/usr/local/gcc --disable-nls --enable-version-specific-runtime-libs --enable-__cxa_atexit --enable-languages=c,c++ and get this: creating cache ./config.cache checking host system type... x86_64-unknown-linux-gnu checking target system type... x86_64-unknown-linux-gnu checking build system type... x86_64-unknown-linux-gnu checking for a BSD compatible install... /usr/bin/install -c checking whether ln works... yes checking whether ln -s works... yes checking for gcc... gcc checking whether the C compiler (gcc ) works... yes checking whether the C compiler (gcc ) is a cross-compiler... no checking whether we are using GNU C... yes checking whether gcc accepts -g... yes checking for gnatbind... no checking whether compiler driver understands Ada... no checking how to compare bootstrapped objects... cmp --ignore-initial=16 $$f1 $$f2 checking for correct version of gmp.h... yes checking for MPFR... no *** This configuration is not supported in the following subdirectories: target-libada gnattools target-libgfortran target-libffi target-boehm-gc target-zlib target-libjava zlib fastjar target-libobjc (Any other directories should still work fine.) checking for bison... bison -y checking for bison... bison checking for gm4... no checking for gnum4... no checking for m4... m4 checking for flex... flex checking for flex... flex checking for makeinfo... makeinfo checking for expect... no checking for runtest... no checking for x86_64-unknown-linux-gnu-ar... no checking for ar... ar checking for x86_64-unknown-linux-gnu-as... no checking for as... as checking for x86_64-unknown-linux-gnu-dlltool... no checking for dlltool... no ... and so on or this: ../gcc-4.1-branch/configure --prefix=/usr/local/gcc --disable-nls --enable-version-specific-runtime-libs --enable-__cxa_atexit --enable-languages=c,c++ --build=x86_64-pc-linux-gnu --host=x86_64-pc-linux-gnu --target=x86_64-pc-linux-gnu and get this: creating cache ./config.cache checking host system type... x86_64-pc-linux-gnu checking target system type... x86_64-pc-linux-gnu checking build system type... x86_64-pc-linux-gnu checking for a BSD compatible install... /usr/bin/install -c checking whether ln works... yes checking whether ln -s works... yes checking for gcc... gcc checking whether the C compiler (gcc ) works... yes checking whether the C compiler (gcc ) is a cross-compiler... no checking whether we are using GNU C... yes checking whether gcc accepts -g... yes checking for gnatbind... no checking whether compiler driver understands Ada... no checking how to compare bootstrapped objects... cmp --ignore-initial=16 $$f1 $$f2 checking for correct version of gmp.h... yes checking for MPFR... no *** This configuration is not supported in the following subdirectories: target-libada gnattools target-libgfortran target-libffi target-boehm-gc target-zlib target-libjava zlib fastjar target-libobjc (Any other directories should still work fine.) checking for bison... bison -y checking for bison... bison checking for gm4... no checking for gnum4... no checking for m4... m4 checking for flex... flex checking for flex... flex checking for makeinfo... makeinfo checking for expect... no checking for runtest... no checking for x86_64-pc-linux-gnu-ar... x86_64-pc-linux-gnu-ar checking for x86_64-pc-linux-gnu-as... x86_64-pc-linux-gnu-as checking for x86_64-pc-linux-gnu-dlltool... no checking for dlltool... no checking for x86_64-pc-linux-gnu-ld... /usr/lib/gcc/x86_64-pc-linux-gnu/3.4.6/../../../../x86_64-pc-linux-gnu/bin/ld checking for x86_64-pc-linux-gnu-lipo... no checking for lipo... no checking for x86_64-pc-linux-gnu-nm... x86_64-pc-linux-gnu-nm checking for x86_64-pc-linux-gnu-ranlib... x86_64-pc-linux-gnu-ranlib checking for x86_64-pc-linux-gnu-strip... x86_64-pc-linux-gnu-strip checking for x86_64-pc-linux-gnu-windres... no checking for windres... no checking for x86_64-pc-linux-gnu-objcopy... x86_64-pc-linux-gnu-objcopy checking for x86_64-pc-linux-gnu-objdump... x86_64-pc-linux-gnu-objdump checking for x86_64-pc-linux-gnu-ar... x86_64-pc-linux-gnu-ar checking for x86_64-pc-linux-gnu-as... x86_64-pc-linux-gnu-as ... and so on, which actually seems to be OK. But both fail like this (or similarly so): config.status: creating Makefile config.status: creating include/Makefile config.status: creating libmath/Makefile config.status: creating libsupc++/Makefile config.status: creating src/Makefile config.status: creating po/Makefile config.status: creating testsuite/Makefile config.status: creating scripts/testsuite_flags config.status: creating config.h config.status: executing default-1 commands Adding multilib support to Makefile in ../../../gcc-4.1-branch/libstdc++-v3 multidirs=32 with_multisubdir= Running configure in multilib subdirs 32 pwd: /home/ayqazi/src/packages/gcc-4.1-svn/gcc-4.1-build/x86_64-pc-linux-gnu/libstdc++-v3 Running configure in multilib subdir 32 pwd: /home/ayqazi/src/packages/gcc-4.1-svn/gcc-4.1-build/x86_64-pc-linux-gnu mkdir 32 configure: creating cache ./config.cache checking build system type... x86_64-pc-linux-gnu checking host system type... x86_64-pc-linux-gnu checking target system type... x86_64-pc-linux-gnu checking for a BSD-compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking for gawk... gawk checking whether make sets $(MAKE)... yes checking for x86_64-pc-linux-gnu-gcc... /home/ayqazi/src/packages/gcc-4.1-svn/gcc-4.1-build/./gcc/xgcc -B/home/ayqazi/src/packages/gcc-4.1-svn/gcc-4.1-build/./gcc/ -B/usr/local/gcc/x86_64-pc-linux-gnu/bin/ -B/usr/local/gcc/x86_64-pc-linux-gnu/lib/ -isystem /usr/local/gcc/x86_64-pc-linux-gnu/include -isystem /usr/local/gcc/x86_64-pc-linux-gnu/sys-include -m32 checking for C compiler default output file name... a.out checking whether the C compiler works... configure: error: cannot run C compiled programs. If you meant to cross compile, use `--host'. See `config.log' for more details. make[3]: *** [configure-target-libstdc++-v3] Error 1 make[3]: Leaving directory `/home/ayqazi/src/packages/gcc-4.1-svn/gcc-4.1-build' make[2]: *** [all] Error 2 make[2]: Leaving directory `/home/ayqazi/src/packages/gcc-4.1-svn/gcc-4.1-build' make[1]: *** [profiledbootstrap] Error 2 make[1]: Leaving directory `/home/ayqazi/src/packages/gcc-4.1-svn/gcc-4.1-build' make: *** [build] Error 2 What's going on? Thanks