PHP on Apache: The Definitive Installation Guide Page 7

Appendix C: Fixing Red Hat 6.1's apxs Script

The apache-devel RPM included in the original Red Hat 6.1 distribution contains a broken version of the apxs script, which will prevent you from using it with PHP (or any other module). It's possible that a later redistribution of 6.1 (such as CDs made and passed around by a Linux user group) may have this problem fixed—but just in case, check /usr/sbin/apxs. If somewhere near line 81 you see

    my     = 'modules';



then change 'modules' to '/usr/lib/apache'. Next,
look for lines that look like this: 
    my       = 'gcc';
    my  = q(-shared);



If the lines in your /usr/sbin/apxs script look something like
this, and the  line has been corrected, you should
be in good shape to build PHP. You can find more details in the
./php/php3/INSTALL.REDHAT file included in the PHP distribution.