Can't unmount external disk used with Music app due to AMPLibraryAgent process

I use an external storage disk for my Music library in macOS 10.15 Catalina, because the required file size is several times my internal SSD. After upgrading to Catalina, now when I connect the drive to use Music, I cannot eject the drive afterward, due to a lock by the AMPLibraryAgent process. Here is terminal output detailing the issue:

diskutil unmountdisk /dev/disk2
Unmount of disk2 failed: at least one volume could not be unmounted
Unmount was dissented by PID 710 (/System/Library/PrivateFrameworks/AMPLibrary.framework/Versions/A/Support/AMPLibraryAgent)
Dissenter parent PPID 1 (/sbin/launchd)

How can I remove this lock without quitting that service process or shutting down my computer?

Solution 1:

You can try force unmounting the drive. It unmounts the drive if some process is already using it.

diskutil unmountdisk force /dev/disk2

Solution 2:

I'm running into the same issue, with Catalina 10.15.2. One slight workaround, sort of, that I found is that instead of having to reboot the machine to cleanly eject the drive, I can log out and then log back in, and then it's been freed up for ejecting. Of course I'd rather not have to do that. But this seems to be a bug that I hope will be fixed.

Solution 3:

I'm having exactly the same issue with my Music(iTunes) Library on my external Drive due to space reasons. macOS 10.15.4

My dodgy workaround is that I have a created a routine with Automator which quits the AMPLibraryAgent process with one click.

Did anyone find a better solution?