Some fun with Ubuntu sandboxes

 Yesterday, since it was a depressing wet and cold day, I spent part of the afternoon upgrading my Lenovo IdeaPad from the previous version of Ubuntu, Jammy Jellyfish, to Noble Numbat, the new version with long term support.

The upgrade went well, the machine rebooted cleanly at the end of the upgrade process and everything worked well, apart from one app - Notable.

This is a little bit unfortunate, for me at least, as Notable is one of the components of my research toolkit.

I use it to create living documents when researching a topic. Notable allows me to organise these notes in a way that makes sense to me, and being markdown based its straightforward to take a note's content and convert it to an .odt or .docx document to insert into something else.

As always after an upgrade, I clicked round the various key applications and they all appeared to work with the exception of Notable.

It simply didn't start.

Now, I'm no longer any sort of Linux expert but I do remember the basics of problem solving.

First of all I tried running it from a terminal, which produced this slightly scary message

which did not look good. I didn't understand the implications but I got the key message - the new version of Ubuntu is using application containers to stop wayward applications writing somewhere where they shouldn't, and this time around the container helper application was not correctly configured.

After a bit of googling I found there was a --no-sandbox argument one could add to the command line but that seemed a bit clunky as an option.

So I tried option B - reinstalling the application using the .deb from the developer website. Didn't work - in retrospect that was probably a silly idea as the installer hadn't been updated for some time, and would have no 'awareness' of the sandbox requirement.

So. option C - try installing from the Snap Store - this worked, but left me with two Notable icons, one to the 'bad' un-sandboxed install, and one to the 'good' install.

I couldn't work out how to get rid of the 'bad' icon, so I simply pinned the 'good' icon to the taskbar, and I'll try and find a fix later - for the moment I've a working tool and I'm happy.

I guess that the better way of doing this (and I have not tried this - I don't feel like experimenting at the moment) is before upgrading to Noble Numbat 

• copy your data somewhere safe 
• uninstall notable 
• upgrade 
• install notable from the snap store 
• re-import your data...