From here: http://markmail.org/message/ov54mrfer3tpyitq#query:apxs%2064-bit%20centos+page:1+mid:ov54mrfer3tpyitq+state:results
You need to force the installation of 64-bit dependencies to make apxs function correctly. I was receiving various useless errors along the lines of LONG_BIT mismatches and "unsupported CPU".
Run:
yum install apr-util-devel.x86_64
yum install expat-devel.x86_64
yum install apr-devel.x86_64
In fact, I ended up doing:
yum remove httpd-devel
yum install httpd-devel.x86_64
Which cleanly removed all the nasty i386 material it had installed.
