pigiRpc process will consume all the available swap and eventually crash. If you feel you need really large delays, James Lundblad suggests writing your own code in your stars that provides the same functionality as delays, but uses malloc() in the initCode section instead of the array that is created by the CGC Delay icon.
main() function of a CGC simulation may be too large for the peephole optimizer, causing the optimizer to take a long time to compile the file. Under gcc, you can pass the -O0 option to turn off the optimizer.