Strange AUv3 Problem (macOS)

In the interests of getting ahead of the fast-approaching curve, I’m beginning to prepare our product line for AUv3 deployment on macOS, and I’m running in to an odd problem.

The AUv3 works fine in Logic (other than, you know, the expected nonsense) and in Reaper. However, in auval I see this:

2020-06-28 09:21:05.894 auvaltool[3233:71507] unable to obtain configuration from 
file:///Library/Preferences/ due to Error 
Domain=NSCocoaErrorDomain Code=260 "The file “” couldn’t 
be opened because there is no such file." UserInfo=. 
NSUnderlyingError=0x7fce30456210 {Error Domain=NSPOSIXErrorDomain Code=2 "No 
such file or directory"}}
2020-06-28 09:21:05.894 auvaltool[3233:71507] *** Assertion failure in +. 
[NSServiceViewController currentAppIsViewService], 
2020-06-28 09:21:05.894 auvaltool[3233:71507] *** Assertion failure in +. 
[NSServiceViewController currentAppIsViewService], 

And the plugin will not instance in Live, which I assume is related. Any thoughts? This is on macOS 10.15, Xcode 11.5, JUCE 5.4.7 dev tip (as of last week, anyhow.)

I have verified that this file, /Library/Preferences/, does not exist on either of my Macs, both of which are Catalina. I do not know what it is for, and the only reference I can find in Developer Connection is to an obscure plist library that references it in FXPlugins (which are, of course, for video.) Anyone know what this is and why the AUv3 needs it?

I acquired that file from a tester that isn’t running Catalina (it doesn’t appear to be present in Catalina installs) and it is just an empty Root dictionary. No idea what it is for. But putting it in /Preferences gets rid of that first error. But both those assertion errors in currentAppIsViewService remain.

Side question: does anyone know if Live actually hosts AUv3 at this point? I don’t have any others to test with.

i thought auvaltool didn’t support auv3?

Of course it does. An AUv3 is bridged to AUv2.

Ableton Live doesn’t host AUv3 plugins, only AU (v2).

Of course it does. An AUv3 is bridged to AUv2.

you’ve blown my mind and now i’m finding even more buggy behavior in my plugin. i can verify that if i don’t have a .component version on disk, auvaltool -al will find the plugin at an unknown url.

Yeah. I’m given to understand that if the .appex is registered, it hands a sort of internal symlink to the auvaltool, so as far as auval (and non-AUv3 hosts) know, there’s a real AU sitting there.

As we’re seeing with Live, this isn’t foolproof, but all other hosts I have can see it. Up until this massive dump of iOS plugins to ARM macOS happens, it will be a very low priority for the DAW people, as no commercial dev I’m aware of ships AUv3. Shit’s about to get cray, though, which is why I’m spending my Sunday experimenting rather than, you know, doing literally anything else.

lol - my current plugin will not work in logic/garageband as an au, but will as an auv3, but won’t if the au component is also installed at the same time.

it also won’t work in live when both the auv3 + au are installed, but will if only the au is installed.

all three options work in reaper so it’s possible somehow ¯\_(ツ)_/¯