From what I see, the file descriptor, used internally by Apple's initWithContentsOfFile() for NSSound, isn't being closed in 10.15. Because of that, there isn't an available file descriptor when trying to create window.prf.new and lore.txt.new. As a quick fix, deleting one of the redundant calls to load_sounds() in main-cocoa.m (I got rid of the one in beginGame()) works for me: that leaves enough available file descriptors for saving the preferences and lore. I'll try to work up some simple sample code to see if this is Apple's bug or if something in main-cocoa.m is to blame.

Thanks for following this up :)

New builds are up on the nightlies page and angband.live (source here) with the following changes:

• Updated Gervais tiles included, kindly provided by Bill Peterson
• A raft of memory leaks fixed (thanks backwardsEric)
• Also due to backwardsEric: improved macOS rendering, and another attempt at fixing the Catalina lore-writing bug
• Nerfs to magic devices, mainly for mages and rogues:
  • Device damage boost removed
  • Tap Magical Energy now stuns the player for 1 or 2 turns, and being stunned cancels FastCast
  • Recharge spells are much more likely to destroy devices (more in line with the scroll)
• Buffs (mostly) to necromancers:
  • The magic light modifier on objects is now reduced by 1 for necros, which means they can wield LIGHT[1] objects without getting an increased spell failure rate
  • Necros now get the EVIL player flag, which gives innate RNether, but vulnerability to orb of draining
  • Some monsters now cast orbs of draining :)

Again, getting rebalance changes out early in the journey to 4.2.1. Voicing of opinions encouraged.

Font seemed to change. There's extra space between characters, making it hard to read in the windows...I had been using fixed width Menlo size 14, but now to make it fit in the inventory window i have to set it to 12 point but there's still extra space between the characters.

But the save bug seems to be fixed. I successfully turned on sound and have saved progress, even started a new game with randarts and it appeared to be working. Thanks.

Agreeing with mrfy, with that nightly build running on MacOS 10.15.2 beta in a virtual machine and sound enabled, I don't see the problem saving lore.txt and window.prf. I filed a report with Apple about NSSound's initWithContentsOfFile leaving a fie descriptor open: that is still present in Mac OS 10.15.2 beta. With that underlying bug present, adding more sounds to sound.cfg has the potential to cause calls to open a file to fail because of the limit on the number of open files for a single process.

The rendering change for the Mac dd increase the size of the rectangle used to render each character and aligned those rectangles on pixel boundaries. Changing line 800 of main-cocoa.m to

would get the horizontal spacing closer to what it was, though you'll still need wider and taller windows to render the same amount of content with the same font as you used with Angband 4.2.0.

Is this the boost from your devices skill?
All sound good to me
Whoa, that all sounds pretty awesome! Has any suggested changing "Nether" to "Wither"? Seems like a more apt title these days, though "Wither Worms" doesn't really please my ear.

Should blackguards also get this flag, since they cast from the same book?

Yes - it's a percentage bonus to damage from when your device skill is greater than the object level. It can be up to 138%.

Maybe, but I'm inclined not to for now - they seem more like casual users of dark arts :)

There's still a bug where you hit an invisible trap, set it off, move past, and it's still invisible. Shouldn't it be visible after you trip it?

My $0.02 I think this is cool and would like to see it kept.