When generating an IP core in the CORE Generator tool, the generation process indicates that it is still running, but does not make any progress over several hours.
If I run CORE Generator in Debug mode, I see that the XST process completes and the console reports that it is "Running ngcbuild"... However, the ngcbuild process then starts, but no more progress is made. Sometimes the ngcbuild process hangs, but other times it appears to exit and the _cg process hangs.
This issue occurs when generating IP cores through the CORE Generator tool in a memory-constrained environment (e.g., Virtual Machine) if the available memory is only slightly over the threshold required to synthesize the IP core. For many IP, this is from 0.8 to 1.2GB of RAM.
To work around this issue: