Intermittent build failure where dwarfsrcfiles doesn't exist

Question

We've been using Dunfell for a while but recently I've started getting an intermittent build failure from an app:

ERROR: my-app-1.0.52-213f116 do_package: Fatal errors occurred in subprocesses:
[Errno 2] No such file or directory: 'dwarfsrcfiles': 'dwarfsrcfiles': Traceback (most recent call last):
  File "/var/lib/jenkins/workspace/la_meta-my-layer_check-build/my-yocto-sdk/poky/meta/lib/oe/utils.py", line 280, in run
    ret = self._target(*self._args, **self._kwargs)
  File "/var/lib/jenkins/workspace/la_meta-my-layer_check-build/my-yocto-sdk/poky/meta/classes/package.bbclass", line 405, in splitdebuginfo
    sources = source_info(file, d)
  File "/var/lib/jenkins/workspace/la_meta-my-layer_check-build/my-yocto-sdk/poky/meta/classes/package.bbclass", line 353, in source_info
    output = subprocess.check_output(cmd, universal_newlines=True, stderr=subprocess.STDOUT)
  File "/usr/lib/python3.7/subprocess.py", line 395, in check_output
    **kwargs).stdout
  File "/usr/lib/python3.7/subprocess.py", line 472, in run
    with Popen(*popenargs, **kwargs) as process:
  File "/usr/lib/python3.7/subprocess.py", line 775, in __init__
    restore_signals, start_new_session)
  File "/usr/lib/python3.7/subprocess.py", line 1522, in _execute_child
    raise child_exception_type(errno_num, err_msg, err_filename)
FileNotFoundError: [Errno 2] No such file or directory: 'dwarfsrcfiles': 'dwarfsrcfiles'

I assumed this was a race condition, so following Debugging Parallel Make Races I added:

PARALLEL_MAKE = ""

to the app recipe, but it didn't seem to help. However, setting:

PARALLEL_MAKE = "-j 20"

does seem to make it fail every time.

The recipe isn't doing anything to the package step so I'm not sure why it's running before dwarfsrcfiles is built. I can see īt's included in poky/meta/classes/package.bbclass but since it's a dependency I would have thought it has to be built before the packaging step can be done?

Is there something I can add to my recipe to stop this happening?

Update: Yes, dwarfsrcfiles is being built and I can run it after the build fails. I've just upgraded this build to Kirkstone and the same thing is happening.