Dear Maintainer,

(I am the maintainer; filing this so the problem is on record before the fix,
since it affects the version currently in unstable.)

helpdev aborts with an unhandled traceback when pip is not installed:

  $ helpdev --packages-pip
  Traceback (most recent call last):
    ...
    File "/usr/lib/python3/dist-packages/helpdev/__init__.py", line 73, in
      _run_subprocess_split
      output = subprocess.check_output(command, shell=False)
  FileNotFoundError: [Errno 2] No such file or directory: 'pip'

Debian does not install pip by default and helpdev does not depend on it, so
this is the behaviour on a stock system.

Affected invocations, tested on a machine with no pip on PATH:

  helpdev                 completes normally (does not reach the pip path)
  helpdev --all           FileNotFoundError
  helpdev --packages-pip  FileNotFoundError
  helpdev --packages      FileNotFoundError