symptom : enabling APXS support for Apache2, no apxs2

solution : yum install httpd-devel

Building PHP with OCI8

problems occur because when configuring for build you get

checking libxml2 install dir... no
checking for xml2-config path...
configure: error: xml2-config not found. Please check your libxml2 installation.
How to solve :
yum install libxml2-devel

and then it works.