non-x86 issue (cmsis-pack-manager dependency)

Trying to run pyocd on Raspberry Pi.

Tried installing dependencies manually and installed pyocd with --no-deps as suggested in installing_on_non_x86.md.
pip3 succeeds installing, but pyocd throws DistributionNotFound at runtime, even when invoked with python3 -m pyocd (see below).

Current workaround is to install from source after removing cmsis-pack-manager from install_requires in setup.py.

$ python3 -m pyocd
Traceback (most recent call last):
  File "/usr/lib/python3.7/runpy.py", line 183, in _run_module_as_main
    mod_name, mod_spec, code = _get_module_details(mod_name, _Error)
  File "/usr/lib/python3.7/runpy.py", line 142, in _get_module_details
    return _get_module_details(pkg_main_name, error)
  File "/usr/lib/python3.7/runpy.py", line 109, in _get_module_details
    __import__(pkg_name)
  File "/home/huesmann/.local/lib/python3.7/site-packages/pyocd/__init__.py", line 21, in <module>
    from . import gdbserver
  File "/home/huesmann/.local/lib/python3.7/site-packages/pyocd/gdbserver/__init__.py", line 17, in <module>
    from .gdbserver import GDBServer
  File "/home/huesmann/.local/lib/python3.7/site-packages/pyocd/gdbserver/gdbserver.py", line 41, in <module>
    from ..rtos import RTOS
  File "/home/huesmann/.local/lib/python3.7/site-packages/pyocd/rtos/__init__.py", line 30, in <module>
    load_plugin_classes_of_type('pyocd.rtos', RTOS, ThreadProvider)
  File "/home/huesmann/.local/lib/python3.7/site-packages/pyocd/core/plugin.py", line 88, in load_plugin_classes_of_type
    plugin = entry_point.load()()
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2410, in load
    self.require(*args, **kwargs)
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 2433, in require
    items = working_set.resolve(reqs, env, installer, extras=self.extras)
  File "/usr/lib/python3/dist-packages/pkg_resources/__init__.py", line 786, in resolve
    raise DistributionNotFound(req, requirers)
pkg_resources.DistributionNotFound: The 'cmsis-pack-manager>=0.2.7' distribution was not found and is required by the application

Start with docs/installing_on_non_x86.md and the dependency declaration in setup.py, then reproduce the python3 -m pyocd failure on a Raspberry Pi or other non-x86 system. Trace the cmsis-pack-manager entry-point loading shown in the report; done means the documented installation starts without DistributionNotFound or requiring a manual setup.py edit.