We haven't been able to get Apple's AUv3 sample code to work reliably across our machines.
I'm referring to the code here: https://developer.apple.com/documentation/audiotoolbox/creating_custom_audio_effects
iMac Pro Late 2017: validates and seems to work
MacBook Pro 15" 2018: auval can't find the plugin
MacBook Pro 15" Late 2013: auval -a segfaults, auval -v afux filtr Demo returns:
Input/Output Channel Handling:
1-1 1-2 1-4 1-5 1-6 1-7 1-8 2-2 2-4 2-5 2-6 2-7 2-8 4-4 4-5 5-5 6-6 7-7 8-8
X X X X X X X
ERROR: -10868 IN CALL Cannot Set Output Num Channels:2 when unit says it can
ERROR: -10868 IN CALL Cannot Set Output Num Channels:4 when unit says it can
ERROR: -10868 IN CALL Cannot Set Output Num Channels:5 when unit says it can
ERROR: -10868 IN CALL Cannot Set Output Num Channels:6 when unit says it can
ERROR: -10868 IN CALL Cannot Set Output Num Channels:7 when unit says it can
ERROR: -10868 IN CALL Cannot Set Output Num Channels:8 when unit says it can
ERROR: -10868 IN CALL Cannot Set Output Num Channels:2 when unit says it can
I've tried deleting ~/Library/Caches/AudioUnitCache and rebooting.
I'm not sure what else to do.