"Nix Store" on disk1s5 couldn't be unmounted because it is in use by securityd

[nmrshll]

Error

Error: 
   0: Error reverting
   0: Action `create_apfs_volume` errored
      Failed to execute command with status 1 `"/usr/sbin/diskutil" "apfs" "deleteVolume" "Nix Store"`, stdout: Started APFS operation
      Deleting APFS Volume from its APFS Container
      Unmounting disk1s5
      The volume "Nix Store" on disk1s5 couldn't be unmounted because it is in use by process 126 (securityd)

      stderr: Error: -69888: Couldn't unmount disk

Metadata

key	value
version	0.13.1
os	macos
arch	x86_64

[nmrshll]

This happened while uninstalling to solve this other issue: #608

Before that:

• I uninstalled a previous nix installation
• I reinstalled using nix-installer
• ran my nix-darwin + home-manager flake: got the cert issue #608
• the solution for the issue involved uninstalling using nix-installer uninstall: got this issue

[Hoverbear]

This is a new one. I wonder what's causing it...