I'm rebuilding a QNX7.1 resource manager that runs well on armv7le (BBB) and x86_64, so I expected the build for RPi4/
aarch64le to work as expected, but as I enter the receive loop:

	while (1) {
		if ((ctp = dispatch_block (ctp)) == NULL) {
			fprintf (stderr, "%s:  dispatch_block failed: %s\n",
					argv[0], strerror (errno));
			exit (1);
		}
		dispatch_handler (ctp);
	}

the process seems to terminate at the dispatch_block() call, where it would normally block.  I've checked the variables 
for dispatch structure and context structure, etc. and nothing looks off.  Am I perhaps forgetting something I need to 
either include in the build file or a process I am not starting?

Thanks for any leads on this!
David