env variables provided by app launcher

[Darren Landoll]

I'm trying to use the SNAP_APP_TMPDIR and SNAP_APP_DATA_PATH
environment variables to store data for my application. After some
initial testing with SNAP_APP_TMPDIR, it appears to be set to "/tmp"
at runtime despite the launcher script setting it to the app specific
path under "/tmp/..." and the app is unable to write data.

Is this a known issue or could I be doing something wrong? I've been
running the app with sudo, not sure if that would make any difference
or not.