I am attempting to cross compile GCC on x86_64 for arm. I created a chroot with the arm system with the target system headers. I configure the build with ${ROOT}/gcc-4.9.4/configure \ --prefix=${ROOT}/toolchain \ --program-prefix=arm-linux-gnueabihf- \ --enable-languages=c,c++ \ --with-gnu-as \ --with-as=${ROOT}/toolchain/bin/arm-linux-gnueabihf-as \ --with-gnu-ld \ --with-ld=${ROOT}/toolchain/bin/arm-linux-gnueabihf-ld \ --with-sysroot=/var/lib/schroot/chroots/trusty-armhf \ --target=arm-linux-gnueabihf \ --disable-multilib \ --disable-nls It succeeds in building the first compiler and then starts to use it ./gcc/xgcc ..... which dies with make[2]: *** [_addvsi3.o] Error 1 In file included from /var/lib/schroot/chroots/trusty-armhf/usr/include/stdio.h:27:0, from /usr/local/suteki/chn_20160901/gcc-4.9.4/libgcc/../gcc/tsystem.h:87, from /usr/local/suteki/chn_20160901/gcc-4.9.4/libgcc/libgcc2.c:27: /var/lib/schroot/chroots/trusty-armhf/usr/include/features.h:374:25: fatal error: sys/cdefs.h: No such file or directory # include <sys/cdefs.h> ^ compilation terminated. The header it cannot find is present but in /var/lib/schroot/chroots/trusty-armhf/usr/include/arm-linux-gnueabihf/sys/cdefs.h It seems only <sysroot>/usr/include is on the search path, not the additional <sysroot>/usr/include/<target> which is needed to find this header. How can I add this search path? Searching for header in the configuration instruction page came up empty...  Michiel.