The configure script appears to hang

If you find that the configure script appears to hang on this line:

checking for redhat spopen problem...

Then you probably have a badly configured DNS server. This part of configure is testing for a pthread problem in BIND that is a kernel problem on some Red Hat derived versions of Linux (around kernel 2.6.9-11). It runs 10 x 100 nslookup calls to see if your kernel has this problem. If it does, then at least one of those calls will fail. Failure rate could be anywhere between 1% and 50%.

To force the workaround and ignore the test, run ./configure with the --enable-redhat-pthread-workaround switch.