How to install a classic confinement snap

Classic confinement gives a snap broad system access similar to a traditional distribution package. Some developer tools and desktop applications need that wider access, so snap install stops and asks for an explicit --classic flag instead of silently weakening the sandbox.

The confinement field in snap info tells whether a package is strict, classic, or intended for devmode testing. A classic snap should be treated as trusted software from the named publisher because it is not limited to the same set of mediated interfaces as a strictly confined snap.

A completed classic install should show the package in snap list with the classic note and expose the expected command. Use the classic flag only for snaps that require it; do not add it to ordinary strict snaps as a troubleshooting shortcut.

1. Inspect the snap confinement before installing it.

   $ snap info snapcraft
   name:      snapcraft
   publisher: Canonical
   summary:  Package, distribute, and update any app for Linux and IoT
   confinement: classic
   channels:
     latest/stable:    8.13.4
     latest/candidate: 8.13.4
     latest/beta:      8.13.5
     latest/edge:      8.13.5

   Classic snaps have wider host access than strict snaps. Install them only from publishers you trust.

2. Install the snap with the --classic flag.

   $ sudo snap install snapcraft --classic
   snapcraft 8.13.4 from Canonical installed

3. Confirm that snapd recorded the classic confinement note.

   $ snap list snapcraft
   Name       Version  Rev   Tracking       Publisher  Notes
   snapcraft  8.13.4   17123 latest/stable  canonical  classic

4. Run the installed command.

   $ snapcraft version
   snapcraft 8.13.4

5. Check the exposed app name when the command is not obvious.

   $ snap apps snapcraft
   App        Version  Notes
   snapcraft  8.13.4   -