gcc build error in pbuilder

root@machine:/root/gcc-4.7.1/build# ../configure --build=x86_64-linux-gnu --prefix=/usr/gcc_4_7 --enable-checking=release --enable-languages=c,c++ --disable-multilib --program-suffix=-4.7
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 ln works... yes
checking whether ln -s works... yes
checking for a sed that does not truncate output... /bin/sed
checking for gawk... gawk
checking for libitm support... yes
checking for gcc... gcc
checking for C compiler default output file name...
configure: error: in `/root/gcc-4.7.1/build':
configure: error: C compiler cannot create executables
See `config.log' for more details.
root@machine:/root/gcc-4.7.1/build# exit