%general-entities; ]> Flex temporary system Make sure that Flex doesn't try to include headers from /usr/include. cp -v Makefile.in{,.orig} sed "s/-I@includedir@//g" Makefile.in.orig > Makefile.in When Cross Compiling the configure script does not determine the correct values for the following, Set the values manually: cat > config.cache << EOF ac_cv_func_malloc_0_nonnull=yes ac_cv_func_realloc_0_nonnull=yes EOF ./configure --prefix=/tools \ --build=${CLFS_HOST} --host=${CLFS_TARGET} \ --cache-file=config.cache