It is a real disaster in iOS12. Previously working programs now just hang at certain points. If you watch it animating the execution by moving a highlight through the code, it just sticks on some line or other. In one program it stuck when doing a query via http, so that looked like a comms failure, but for no good reason. But in a copy of the same program, slightly edited to put more debug info in, it then hung at a completely different point, this time in a regex search-and-replace filtering verb operating on a string, which cannot possibly take forever anyway. And it is a known working tested app.
Was on to Apple support about all the bugs, then they insisted on phoning me rather than internet chat and got cut off because of no signal.
