Appdirs can return non writable directories

[hmaarrfk]

It seems like appdirs can return a directory that cannot be written to.

Is this an expected feature?

scikit-image/scikit-image#4664

From the original user:

For my flask app's service, the user is a no-login user, and somehow this resolves to /var/www/.
The user doesn't have permissions to create a directory there, so the flask app crashes with a PermissionError raised from.

[leducvin]

Leaving a few more details on scikit-image/scikit-image#4664... for my flask app running under user www-data, the home directory is /var/www. Here is the output of getent passwd www-data:

www-data:x:33:33:www-data:/var/www:/usr/sbin/nologin

When appdirs.user_cache_dir() gets called, it returns /var/www/.cache. This is read-only.

[zoofood]

Thanks for sending along the information @hmaarrfk and @leducvin.

Appdirs doesn't do tests of the viability of a directory for writing content to it. It provides what the directory should be according to the XDG spec, effectively $HOME or set the XDG environment variable XDG_CACHE_HOME.

[hmaarrfk]

thanks for the confirmation that this is the intended behavior