Unable to connect to USB Device (Ubuntu Snap)

Hello I'm having trouble connecting my installation of Octaprint to my printer. I installed Octaprint using Snap on Ubuntu 18.04. The same printer works with a Rasperry PI running OctoPi but I just wanted to centralize my install.

The terminal error I receive is exactly the same as what this user experienced - Unexpected error while connecting to serial port: /dev/ttyUSB0

Unfortunately, the chmod command that user used does not work for me.

This is the latest version of Octorpint from the Snapstore and my printer is a ANYCUBIC MEGA-S

Also I wanted to say that this software is absolutely amazing, thanks so much for the awesome work!

Snap is Linux's me-too version of either Apple's app/iTunes provisioning and containment or perhaps Windows 10's new Metro app packaging. It's completely different.

For one, I'm guessing that @foosel didn't publish this on the Snapcraft store and therefore can't control the versions.

The latest release of OctoPrint is 1.3.11 so the "latest" on Snapcraft appears to be a rather old image, to be honest. As you can see from their installation help page, there's nothing really useful at all about the content:

I would advise you not to install some unmanaged snap version of OctoPrint on anything.

Correct. This is out of my control, and I currently also have no idea who manages it.

If it were me I'd tell him to take it down. Who's to say what's in the snap? Just because it has your product name and logo, that doesn't mean that it's legitimate.

From their Terms and Conditions page:

  1. Definitions

  2. App(s): one or more applications or content items owned by you which you submit through the Developer Site and any associated screen shots and marketing materials provided by you, these may be Snappy Ubuntu apps.

Clearly, OctoPrint isn't owned by James Tigert. All he did was fork an old version of OctoPrint and create a yaml file for snapcraft.

Oh and the Snapcraft.io store is a store. They sell apps there, by the way.


Wow I didn't realize I opened up a can of worms. Thanks for all the replies.

Ok I'll kill my snap octoprint and try again with the latest version. Is this still the best guide for getting going on Ubuntu or other linux distros?

I now know who maintains it and based on past interaction I'm very sure there's only good intent behind it, so put the pitchforks back in storage :wink:

I've still tried to reach out.

That would be your best guide. If I were to guess, I don't think the average Linux-loving person will ultimately embrace a store-based style of app delivery and snaps won't endure the test of time.

I got it to work following the instructions except the auto start on boot isn't working but that should be easy enough to fix.

Thanks to everyone for the help and thanks again for the incredible software.

1 Like

Here's the init.d-related file from the OctoPi image.