[Zope] I cannot compile Zope...

...on RedHat 6.2 (Zoot). I did not have problems compiling Zope 2.0 thru 2.2 on earlier versions of RH (eg, 5.2, 6.1). The problem seems to be with finding the include files, among them asm/socket.h. I have played around with LD_LIBRARY_PATH etc but so far have not gotten anything to compile -- not Zope, not ZDiscussions, etc. I have installed the binary version of Zope and this works fine, but that does not come with pcgi-wrapper compiled, for example. Any suggestions?