Hi, My system is ubuntu 14.04 LTS 64 bit and I've installed build-essential. Also tried purge and reinstall libc6-dev. Doesn't work. The information is the follow: from /home/ce/gcc-4.8.2-build/../gcc-4.8.2/libgcc/libgcov.c:27: /usr/include/features.h:374:25: fatal error: sys/cdefs.h: No such file or directory # include <sys/cdefs.h> ^ compilation terminated. make[5]: *** [_gcov.o] Error 1 make[5]: Leaving directory `/home/ce/gcc-4.8.2-build/x86_64-unknown-linux-gnu/32/libgcc' make[4]: *** [multi-do] Error 1 make[4]: Leaving directory `/home/ce/gcc-4.8.2-build/x86_64-unknown-linux-gnu/libgcc' make[3]: *** [all-multi] Error 2 make[3]: *** Waiting for unfinished jobs.... make[3]: Leaving directory `/home/ce/gcc-4.8.2-build/x86_64-unknown-linux-gnu/libgcc' make[2]: *** [all-stage1-target-libgcc] Error 2 make[2]: Leaving directory `/home/ce/gcc-4.8.2-build' make[1]: *** [stage1-bubble] Error 2 make[1]: Leaving directory `/home/ce/gcc-4.8.2-build' make: *** [all] Error 2 Thanks a lot for your help in advance. Ce Qi