Unhandled PermissionError in autoload.py on macOS Mojave due to walking the filesystem

[rben01]

In macOS Mojave, Apple has introduced a permissions system for the data in a user's home folder. With this system, the user may grant or deny permission for an app to access certain sensitive pieces of user data. The sensitive areas mirror what's on iOS and protected data includes Contacts, Calendars, Photos, etc. If the user denies an app permission to access these areas, all operations that the app performs on them, or the folders containing that data, will fail.

When prospector starts up, it does a walk of the user's (current working?) directory, and may attempt to access files that the controlling program (a GUI editor, say) doesn't have permission to access -- especially if the directory is ~. When this happens, instead of failing gracefully, prospector has a hard crash due to the PermissionError caused by attempting to walk through denied directories such as ~/Pictures/Photos Library.photoslibrary.

Here is a sample stack trace:

Traceback (most recent call last):
  File "/opt/miniconda3/bin/prospector", line 10, in <module>
    sys.exit(main())
  File "/opt/miniconda3/lib/python3.6/site-packages/prospector/run.py", line 154, in main
    config = ProspectorConfig()
  File "/opt/miniconda3/lib/python3.6/site-packages/prospector/config/__init__.py", line 34, in __init__
    self.libraries = self._find_used_libraries(self.config, self.profile)
  File "/opt/miniconda3/lib/python3.6/site-packages/prospector/config/__init__.py", line 169, in _find_used_libraries
    map(libraries.append, autodetect_libraries(self.workdir))
  File "/opt/miniconda3/lib/python3.6/site-packages/prospector/autodetect.py", line 94, in autodetect_libraries
    libraries = find_from_path(path)
  File "/opt/miniconda3/lib/python3.6/site-packages/prospector/autodetect.py", line 51, in find_from_path
    names |= find_from_path(item_path)
  File "/opt/miniconda3/lib/python3.6/site-packages/prospector/autodetect.py", line 51, in find_from_path
    names |= find_from_path(item_path)
  File "/opt/miniconda3/lib/python3.6/site-packages/prospector/autodetect.py", line 46, in find_from_path
    for item in os.listdir(path):
PermissionError: [Errno 1] Operation not permitted: '/Users/rben01/Pictures/Photos Library.photoslibrary'

[carlio]

This is an old bug but it's probably the same underlying cause as #487 which is now fixed as of prospector 1.7.2