Hi, I want to install gcc-4.3.0 on my machine. What I did is: svn co svn://gcc.gnu.org/svn/gcc/trunk gcc-4.3.0 Then I downloaded gmp-4.2.2 and mpfr-2.3.0 and put them under directory gcc-4.3.0. Rename them as gmp and mpfr respectively. Then I typed: mkdir bld cd bld ../gcc/configure --prefix=`pwd` --with-gmp --with--mpfr But I got the following error message: checking build system type... i686-pc-linux-gnu checking host system type... i686-pc-linux-gnu checking target system type... i686-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 for C compiler default output file name... a.out checking whether the C compiler works... yes checking whether we are cross compiling... no checking for suffix of executables... checking for suffix of object files... o checking whether we are using the GNU C compiler... yes checking whether gcc accepts -g... yes checking for gcc option to accept ANSI C... none needed checking for g++... g++ checking whether we are using the GNU C++ compiler... yes checking whether g++ accepts -g... yes checking for gnatbind... gnatbind checking for gnatmake... gnatmake checking whether compiler driver understands Ada... yes checking how to compare bootstrapped objects... cmp --ignore-initial=16 $$f1 $$f2 checking for correct version of gmp.h... yes checking for correct version of mpfr.h... no configure: error: Building GCC requires GMP 4.1+ and MPFR 2.2.1+. Try the --with-gmp and/or --with-mpfr options to specify their locations. Copies of these libraries' source code can be found at their respective hosting sites as well as at ftp://gcc.gnu.org/pub/gcc/infrastructure/. See also http://gcc.gnu.org/install/prerequisites.html for additional info. If you obtained GMP and/or MPFR from a vendor distribution package, make sure that you have installed both the libraries and the header files. They may be located in separate packages. Then I checked where gmp was installed previosuly and I got: /usr/share/doc/gmp-4.1.2 /usr/share/doc/gmp-4.1.2/COPYING /usr/share/doc/gmp-4.1.2/NEWS /usr/share/doc/gmp-4.1.2/README /usr/share/info/gmp.info-1.gz /usr/share/info/gmp.info-2.gz /usr/share/info/gmp.info-3.gz /usr/share/info/gmp.info-4.gz /usr/share/info/gmp.info-5.gz /usr/share/info/gmp.info-6.gz /usr/share/info/gmp.info-7.gz /usr/share/info/gmp.info-8.gz /usr/share/info/gmp.info-9.gz /usr/share/info/gmp.info.gz /usr/include/gmp-mparam.h /usr/include/gmp.h /usr/include/linux/igmp.h /usr/include/netinet/igmp.h /usr/lib/libgmp.so.3.3.2 /usr/lib/libgmp.so.3 /usr/lib/perl5/5.8.0/i386-linux-thread-multi/linux/igmp.ph /usr/lib/libgmp.a /usr/lib/libgmp.so /usr/lib/i386-redhat-linux7/include/netinet/igmp.h /usr/src/linux-2.4.21-37.EL/include/linux/igmp.h /usr/src/linux-2.4.21-37.EL/net/ipv4/igmp.c Is it because mpfr is not consistant with gmp? How can I solve this problem? Thanks very much in advance. With Best Regards, Qin