PHP 5.2.1 installation error
After you have installed your Apache2, and you want to compile PHP5.2.1 into it, and during the ./configure you face problem as below:
checking for IMAP Kerberos support... no
checking for IMAP SSL support... yes
checking for utf8_mime2text signature... new
checking for U8T_CANONICAL... no
configure: error: utf8_mime2text() has new signature, but U8T_CANONICAL is missing. This should not happen. Check config.log for additional information.
This can be solve by just installing the libc-client.i386 and libc-client-devel.i386
yum install libc-client.i386 libc-client-devel.i386
Then try to recompile your php again, this shall work.