Errors out 'Profile is currently in use' when trying again after an error

[seb128]

Trying to buil a 20.10 desktop image

$ sudo -E old-fashioned-image-build --series groovy --image-target squashfs --project ubuntu --subproject live

fails on not found hwe packages (that's not the error report here though)

After that trying any build is failing on that error

+ /usr/share/launchpad-buildd/bin/in-target mount-chroot --backend=lxd --series=focal --arch=amd64 LOCAL_IMAGES_BUILD
Starting target for build LOCAL_IMAGES_BUILD
Traceback (most recent call last):
  File "/usr/share/launchpad-buildd/bin/in-target", line 27, in <module>
    sys.exit(main())
  File "/usr/share/launchpad-buildd/bin/in-target", line 23, in main
    return args.operation.run()
  File "/usr/lib/python3/dist-packages/lpbuildd/target/lifecycle.py", line 42, in run
    self.backend.start()
  File "/usr/lib/python3/dist-packages/lpbuildd/target/lxd.py", line 370, in start
    self.create_profile()
  File "/usr/lib/python3/dist-packages/lpbuildd/target/lxd.py", line 312, in create_profile
    old_profile.delete()
  File "/usr/lib/python3/dist-packages/pylxd/models/_model.py", line 196, in delete
    response = self.api.delete()
  File "/usr/lib/python3/dist-packages/pylxd/client.py", line 148, in delete
    self._assert_response(response, allowed_status_codes=(200, 202))
  File "/usr/lib/python3/dist-packages/pylxd/client.py", line 91, in _assert_response
    raise exceptions.LXDAPIException(response)
pylxd.exceptions.LXDAPIException: Profile is currently in use