snap info does not report channels if unsquashed files are present

[Alfonso Sanchez-Beato]

$ snap download snapd
$ unsquashfs -d snapd snapd_18357.snap
$ ls snapd
bin etc lib lib64 meta snap usr var

$ snap info snapd
path: "snapd/"
name: snapd
summary: Daemon and tooling that enable snap packages
version: 2.56.2 snapd
license: GPL-3.0
description: |
  Install, configure, refresh and remove snap packages. Snaps are
  'universal' packages that work across many different Linux systems,
  enabling secure distribution of the latest apps and utilities for
  cloud, servers, desktops and the internet of things.

  Start with 'snap list' to see installed snaps.
type: snapd

$ rm -rf snapd

$ snap info snapd
name: snapd
summary: Daemon and tooling that enable snap packages
publisher: Canonical✓
store-url: https://snapcraft.io/snapd
license: GPL-3.0
description: |
  Install, configure, refresh and remove snap packages. Snaps are
  'universal' packages that work across many different Linux systems,
  enabling secure distribution of the latest apps and utilities for
  cloud, servers, desktops and the internet of things.

  Start with 'snap list' to see installed snaps.
type: snapd
snap-id: PMrrV4ml8uWuEUDBT8dSGnKUYbevVhc4
tracking: latest/stable
refresh-date: hace 15 días, a las 07:30 GMT
channels:
  latest/stable: 2.58.2 2023-02-15 (18357) 52MB -
  latest/candidate: 2.58.2 2023-02-06 (18357) 52MB -
  latest/beta: 2.58.3 2023-02-22 (18596) 52MB -
  latest/edge: 2.58.3+git546.g8ede977 2023-03-02 (18659) 55MB -
installed: 2.58.2 (18357) 52MB snapd