I've opened a DTS case for this, after upgrading 3 machines to 12.7.3 and Command Line Tools for Xcode 13.4 (14.2 on one machine). The failures are still intermittent.

It works fine on another machine, 12.7.2.

This is on macOS 10.15.7. I have a suspicion that it has something to do with older macOS versions.

Spoke too soon. It just seems random and it randomly worked when I removed --ignore-resources. Now it just failed without it. @eskimo this is a huge issue for me. What can I do to provide you info to help solve this?

So, it appears that --ignore-resources along with --timestamp is the cause. When I remove the former it works for me. This just started failing a few days ago, though. VERY disconcerting. The --ignore-resources was added 7 or so years ago to workaround a problem with codesigning. That was before we used notarization, so I think I'll remove it. @eskimo is this a new, known issue?

@eskimo Re: Coral Software. That version of Allegro was separate from Franz's Allegro CL--they shared no code. It's a pretty strange story. Honestly, I don't even remember the details very well, even though I was around at the time. It was a marketing deal and not technical, so I know why I don't remember. :) Right. That assumes that folks use your language interactively. If you allow folks to take their code and bundle it up into a standalone Mac app, that app will also have to deal with this issue. Do you support such a feature? Our Lisp (and all Lisps) are definitely interactive, but that's a myth that has persisted for too long. You can do scripting and building from make just like you can with C. And you can deliver standalone images with Allegro CL. The reason it's not a problem is that the actual binary image doesn't change when an app is bundled up. Only the "heap" image (a file with extension .dxl) changes. The signed binary with all the entitlements is still there. If they distribute an application with SSL, then they definitely have to worry about the issue just like we do, though.