Install problems with php-4.0RC1and Linux 6.0

Hello, System configuration: Linux 6.0 and php-4.0RC1 with Apache 1.3.9 with mod_so.c loaded Downloade, gunziped, untared into /usr/local/src. Issued command: ./configure --with-mysql --with-apxs Died shortly there after as follows: checking for a BSD compatible install... /usr/bin/install -c checking whether build environment is sane... yes checking whether make sets ${MAKE}... yes checking for working aclocal... missing checking for working autoconf... missing checking for working automake... missing checking for working autoheader... missing checking for working makeinfo... missing checking whether to enable maintainer-specific portions of Makefiles... no checking host system type... i686-pc-linux-gnu checking for bison... bison -y checking bison version... 1.27 (ok) checking for gcc... gcc checking whether the C compiler (gcc ) works... yes checking whether the C compiler (gcc ) is a cross-compiler... no checking whether we are using GNU C... yes checking whether gcc accepts -g... yes checking how to run the C preprocessor... gcc -E checking for AIX... no checking for gcc option to accept ANSI C... none needed checking for ranlib... ranlib checking whether gcc and cc understand -c and -o together... yes checking whether ln -s works... yes checking for flex... no checking for lex... no ./configure: flex: command not found checking for flex... lex checking for yywrap in -ll... no checking lex output file root... ./configure: lex: command not found configure: error: cannot find output from lex; giving up Any thoughts would be appreciated, Chuckc