PHP configuration error

[meander]

i am having a problemwith installation when it gets to the PHP configuration part. here is the error that i am getting:

creating cache ./config.cache
checking host system type... i686-pc-linux-gnu
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 whether gcc and cc understand -c and -o together... yes
checking how to run the C preprocessor... gcc -E
checking for AIX... no
checking if compiler supports -R... no
checking if compiler supports -Wl,-rpath,... yes
checking for re2c... exit 0;
checking whether ln -s works... yes
checking for mawk... no
checking for gawk... gawk
checking for bison... no
checking for byacc... no
configure: warning: You will need bison if you want to regenerate the PHP parsers.
checking for flex... lex
checking for yywrap in -ll... no
checking lex output file root... ./configure: line 2422: lex: command not found
configure: error: cannot find output from lex; giving up
ERROR: Could not configure PHP

[falko]

You have to install flex before you install ISPConfig. On Debian you would run

apt-get install flex

to do so.

[meander]

ok i got that but now i am getting a new error:

configure: error: The installed zlib version may contain a security bug. Please upgrade to 1.2.2 or later: http://www.zlib.net. You can omit this check with --disable-zlib-vcheck but DO NOT REPORT any stability issues then!
ERROR: Could not configure ClamAV

do i have to start all over again? because it takes over an hour to install

[falko]

Please have a look here: http://www.howtoforge.com/forums/showthread.php?t=302