%general-entities; ]> Grep temporary system 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} \ --without-included-regex --cache-file=config.cache --without-included-regex When cross-compiling, Grep's configure assumes there is no usable regex.h installed and instead uses the one included with Grep. This switch forces the use of the regex functions from EGLIBC.