Make Grouse work with snapcraft hugo

[capnfabs]

Hugo installed with snapcraft doesn't work with Grouse, because snapcraft has a super restrictive set of permissions by default that doesn't let Hugo write to / read from existing temporary directories. Instead, snaps have their own private view of /tmp (as per here)

I don't know if I want to bother addressing this just yet -- but we ran into it in this discussion and I wanted to track it.

Some ideas:

• Work out if it's possible to grant permissions / mount directories into a snap's FS layout?
• Symlink / hardlink from the temp directory to the /home/ directory?
• Have a fallback mode that puts all grouse storage in e.g. $HOME/grouse-diff, which would work around this problem. But then, we'd need a strategy for cleaning everything up afterwards (temp files don't have this problem because they're deleted automatically from time-to-time)

[danyelf]

I'll add a +1 to this. With apt-get for Hugo still stuck at 0.68, snap is the cleanest way to keep hugo up to date.

[capnfabs]

Yep! I don't have time to work on this at the moment, but (for future implementers, also if it's me!) I'd go with the last option mentioned above. The complex bit is building a strategy for cleaning up the $HOME/grouse-diff directory periodically, and figuring out how to integrate that with the shenanigans that grouse uses to ensure fast checkouts.