Critical Bug. Snap package uninstallation became permanently stuck. Reinstalling snapd did not resolve the issue. The problem was only fixed after reinstalling the entire Kubuntu system

[Pavol]

Dear Developers,
I had a challenging and frustrating experience with snapd.
Your task is to diagnose these errors and, if possible, to prevent this type of bug from recurring in future development.
The error began when I attempted to uninstall the Opera snap version. However, the uninstallation process became stuck and could not be resolved by any means. Subsequently, I uninstalled the entire snapd package and deleted all associated snap data, but even this extreme measure did not help.
I ultimately solved the problem by completely reinstalling the entire Kubuntu system.
I had a very bad day yesterday, spending the entire day only repairing my computer due to this snapd bug. This is a critical error and should be prioritized for immediate repair.
All software versions were current; the operating system was Kubuntu 25.10.
The root cause of the failure appears to be related to the mounting and initialization of fundamental Snap system components (such as loop devices, core, bare).
Any attempts to install a Snap (e.g., Opera, Firefox, LosslessCut) failed with a mounting error (cannot proceed, expected snap X to be mounted but is not).
**********************************************************

BUG REPORT: Persistent "remove-snap" Deadlock (ID 298)
Title: Snap "opera" permanently blocked in "remove-snap" state despite database repair attempts.
Snapd Version: (Fill in your version, e.g., from snap version command) Distribution: Kubuntu (or your current distribution)
Problem Description
Upon attempting to remove the opera snap package, transaction ID 298 is permanently stuck in Undo / Hold status. This error blocks all further actions (remove, install) for this snap, creating a permanent deadlock.

Command snap remove opera
error: snap "opera" has "remove-snap" change in progress

Command snap list opera - 411 latest/stable opera-software✓ disabled,broken

Command snap changes
Transaction ID 298 is permanently in Undo status.
Log Error ERROR failed to remove snap "opera" base directory: remove /home/uzivatel/snap/opera: directory not empty (The initial error that triggered the failed Undo.)
*************************************************************************
sudo snap remove opera
[sudo: authenticate] Password:
error: snap "opera" has "remove-snap" change in progress

*********************************
 $  uzivatel@uzivatel  ~  sudo snap abort 298
 $  uzivatel@uzivatel  ~  sudo systemctl restart snapd
 $  uzivatel@uzivatel  ~  sudo snap remove opera
error: snap "opera" has "remove-snap" change in progress
 $  uzivatel@uzivatel  ~  snap changes
ID   Status  Spawn               Ready               Summary
280  Done    today at 13:05 CET  today at 13:05 CET  Running service command for snap "onlyoffice-ds"
281  Done    today at 13:05 CET  today at 13:05 CET  Running service command for snap "onlyoffice-ds"
282  Done    today at 13:10 CET  today at 13:11 CET  Pre-download "firefox" for auto-refresh
283  Done    today at 13:10 CET  today at 13:15 CET  Auto-refresh snap "opera"
284  Done    today at 14:18 CET  today at 14:18 CET  Auto-refresh snap "firefox"
285  Done    today at 14:19 CET  today at 14:19 CET  Running service command for snap "onlyoffice-ds"
286  Done    today at 14:19 CET  today at 14:19 CET  Running service command for snap "onlyoffice-ds"
287  Done    today at 14:39 CET  today at 14:39 CET  Connect opera:wayland to snapd:wayland
288  Done    today at 15:53 CET  today at 15:55 CET  Install "beekeeper-studio" snap from "latest/stable" channel
289  Done    today at 15:58 CET  today at 15:58 CET  Remove "beekeeper-studio" snap
290  Done    today at 17:23 CET  today at 17:23 CET  Running service command for snap "onlyoffice-ds"
291  Done    today at 17:23 CET  today at 17:23 CET  Running service command for snap "onlyoffice-ds"
292  Done    today at 17:55 CET  today at 17:55 CET  Connect losslesscut:wayland to snapd:wayland
293  Done    today at 17:55 CET  today at 17:55 CET  Connect opera:wayland to snapd:wayland
294  Done    today at 17:55 CET  today at 17:55 CET  Connect opera:wayland to snapd:wayland
295  Done    today at 17:55 CET  today at 17:55 CET  Connect losslesscut:wayland to snapd:wayland
296  Done    today at 18:10 CET  today at 18:10 CET  Remove "losslesscut" snap
297  Done    today at 18:10 CET  today at 18:10 CET  Install "losslesscut" snap from "latest/stable" channel
298  Undo    today at 18:33 CET  -                   Remove "opera" snap
299  Done    today at 18:40 CET  today at 18:40 CET  Running service command for snap "onlyoffice-ds"
300  Done    today at 18:40 CET  today at 18:40 CET  Running service command for snap "onlyoffice-ds"

 $  uzivatel@uzivatel  ~  sudo snap abort 298
 $  uzivatel@uzivatel  ~  sudo snap abort 283
error: cannot abort change 283 with nothing pending
 $  uzivatel@uzivatel  ~  sudo snap abort 287
error: cannot abort change 287 with nothing pending
 $  uzivatel@uzivatel  ~  sudo snap abort 293
error: cannot abort change 293 with nothing pending
 $  uzivatel@uzivatel  ~  sudo snap abort 294
error: cannot abort change 294 with nothing pending
 $  uzivatel@uzivatel  ~  sudo snap abort 298
 $  uzivatel@uzivatel  ~  sudo snap abort 298
 $  uzivatel@uzivatel  ~  sudo systemctl restart snapd
 $  uzivatel@uzivatel  ~  killall opera
opera: no process found
 $  uzivatel@uzivatel  ~  sudo snap remove opera
error: snap "opera" has "remove-snap" change in progress
 $  uzivatel@uzivatel  ~ 
********************
 $  uzivatel@uzivatel  ~  sudo snap tasks 298
Status  Spawn               Ready               Summary
Undo    today at 18:33 CET  today at 18:33 CET  Stop snap "opera" services
Undo    today at 18:33 CET  today at 18:33 CET  Run remove hook of "opera" snap if present
Done    today at 18:33 CET  today at 18:50 CET  Disconnect interfaces of snap "opera"
Undone  today at 18:33 CET  today at 18:35 CET  Save data of snap "opera" in automatic snapshot set #13
Undone  today at 18:33 CET  today at 18:35 CET  Remove aliases for snap "opera"
Undone  today at 18:33 CET  today at 18:35 CET  Make snap "opera" unavailable to the system
Undone  today at 18:33 CET  today at 18:35 CET  Remove security profile for snap "opera" (411)
Done    today at 18:33 CET  today at 18:50 CET  Remove data for snap "opera" (406)
Done    today at 18:33 CET  today at 18:50 CET  Remove snap "opera" (406) from the system
Error   today at 18:33 CET  today at 18:35 CET  Remove data for snap "opera" (411)
Hold    today at 18:33 CET  today at 18:35 CET  Remove snap "opera" (411) from the system
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:gsettings from snapd:gsettings
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:pulseaudio from snapd:pulseaudio
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:home from snapd:home
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:audio-playback from snapd:audio-playback
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:browser-sandbox from snapd:browser-support
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:wayland from snapd:wayland
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:gnome-42-2204 from gnome-42-2204:gnome-42-2204
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:network from snapd:network
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:unity7 from snapd:unity7
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:screen-inhibit-control from snapd:screen-inhibit-control
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:opengl from snapd:opengl
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:removable-media from snapd:removable-media
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:sound-themes from gtk-common-themes:sound-themes
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:upower-observe from snapd:upower-observe
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:chromium-ffmpeg-121586 from chromium-ffmpeg:chromium-ffmpeg-121586
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:gtk-3-themes from gtk-common-themes:gtk-3-themes
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:desktop-legacy from snapd:desktop-legacy
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:u2f-devices from snapd:u2f-devices
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:camera from snapd:camera
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:desktop from snapd:desktop
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:x11 from snapd:x11
Undone  today at 18:33 CET  today at 18:35 CET  Disconnect opera:icon-themes from gtk-common-themes:icon-themes

......................................................................
Make snap "opera" unavailable to the system

2025-11-26T18:35:26+01:00 INFO cannot link snap "opera" back, some of its data has already been removed

......................................................................
Remove data for snap "opera" (411)

2025-11-26T18:35:26+01:00 ERROR failed to remove snap "opera" base directory: remove /home/uzivatel/snap/opera: directory not empty

 $  uzivatel@uzivatel  ~  sudo systemctl stop snapd
Stopping 'snapd.service', but its triggering units are still active:
snapd.socket
 $  uzivatel@uzivatel  ~  sudo umount -l /var/snap/opera/common/ns
umount: /var/snap/opera/common/ns: no mount point specified.
 $  uzivatel@uzivatel  ~  sudo umount -l /snap/opera/*
 $  uzivatel@uzivatel  ~  sudo systemctl start snapd
 $  uzivatel@uzivatel  ~  sudo snap remove opera
error: snap "opera" has "remove-snap" change in progress
****************************

 $  uzivatel@uzivatel  ~  sudo snap remove opera
[sudo: authenticate] Password:
error: snap "opera" has "remove-snap" change in progress
 $  uzivatel@uzivatel  ~  sudo systemctl stop snapd.socket snapd.service
 $  uzivatel@uzivatel  ~  sudo umount -l /snap/opera/* 2>/dev/null
 $  uzivatel@uzivatel  ~  sudo umount -l /var/snap/opera/common/ns 2>/dev/null
 $  uzivatel@uzivatel  ~  sudo rm -rf /home/uzivatel/snap/opera
 $  uzivatel@uzivatel  ~  sudo rm -rf /var/snap/opera
 $  uzivatel@uzivatel  ~  sudo rm -rf /var/lib/snapd/snaps/opera_*.snap
 $  uzivatel@uzivatel  ~  sudo systemctl start snapd.socket snapd.service
 $  uzivatel@uzivatel  ~  sudo snap abort 298
 $  uzivatel@uzivatel  ~  snap list
Name                    Version                          Rev    Tracking         Publisher             Notes
bare                    1.0                              5      latest/stable    canonical✓            base
chromium                142.0.7444.175                   3313   latest/stable    canonical✓            -
chromium-ffmpeg         120726-120170-119605-119293-etc  88     latest/stable    canonical✓            -
core18                  20251029                         2976   latest/stable    canonical✓            base
core20                  20250822                         2682   latest/stable    canonical✓            base
core22                  20251009                         2163   latest/stable    canonical✓            base
core24                  20251001                         1225   latest/stable    canonical✓            base
cups                    2.4.12-2                         1130   latest/stable    openprinting✓         -
firefox                 145.0.2-1                        7423   latest/stable/…  mozilla✓              -
gnome-3-28-1804         3.28.0-19-g98f9e67.98f9e67       198    latest/stable    canonical✓            -
gnome-3-38-2004         0+git.efb213a                    143    latest/stable    canonical✓            -
gnome-42-2204           0+git.837775c-sdk0+git.7b07595   226    latest/stable/…  canonical✓            -
gnome-46-2404           0+git.df85349-sdk0+git.54e4d8f   145    latest/stable    canonical✓            -
gnome-calculator        48.1                             972    latest/stable    canonical✓            -
gtk-common-themes       0.1-81-g442e511                  1535   latest/stable/…  canonical✓            -
gtk-theme-breeze        1.3                              5      latest/stable/…  kde✓                  -
icon-theme-breeze       1.3                              5      latest/stable/…  kde✓                  -
losslesscut             3.67.1                           139    latest/stable    mifino                -
mesa-2404               25.0.7-snap211                   1165   latest/stable    canonical✓            -
ocrmypdf                v16.4.2+git1.39010dd2            171    latest/stable    shael7aerien          -
ocrthypdf               v0.7.0-65-g92959b4               169    latest/stable    digidigital-software  -
onlyoffice-ds           9.0.4                            741    latest/stable    onlyoffice✓           -
opera                   -                                411    latest/stable    opera-software✓       disabled,broken
snapd                   2.72                             25577  latest/stable    canonical✓            snapd
thunderbird             140.5.0esr-2                     877    latest/stable    canonical✓            -
whisper-gael            v20250625                        8      latest/stable    gael-legoff           -
wine-platform-6-stable  6.0.4                            19     latest/stable    mmtrt                 -
wine-platform-runtime   v1.0                             397    latest/stable    mmtrt                 -
 $  uzivatel@uzivatel  ~  ^C
 $  uzivatel@uzivatel  ~  sudo snap tasks 411
error: cannot find change with id "411"
 $  uzivatel@uzivatel  ~  sudo snap remove opera
error: snap "opera" has "remove-snap" change in progress
*************************
 $  uzivatel@uzivatel  ~  sudo systemctl stop snapd.socket snapd.service
 $  uzivatel@uzivatel  ~  sudo snapctl forget 298
error: cannot communicate with server: Post "http://localhost/v2/snapctl": dial unix /run/snapd-snap.socket: connect: connection refused
 $  uzivatel@uzivatel  ~  sudo systemctl stop snapd.socket snapd.service
 $  uzivatel@uzivatel  ~  sudo rm -f /var/lib/snapd/seq
 $  uzivatel@uzivatel  ~  sudo rm -f /var/lib/snapd/lock/*
 $  uzivatel@uzivatel  ~  sudo systemctl start snapd.socket snapd.service
 $  uzivatel@uzivatel  ~  sudo snap abort 298
 $  uzivatel@uzivatel  ~  snap changes
sudo snap remove opera
ID   Status  Spawn               Ready               Summary
280  Done    today at 13:05 CET  today at 13:05 CET  Running service command for snap "onlyoffice-ds"
281  Done    today at 13:05 CET  today at 13:05 CET  Running service command for snap "onlyoffice-ds"
282  Done    today at 13:10 CET  today at 13:11 CET  Pre-download "firefox" for auto-refresh
283  Done    today at 13:10 CET  today at 13:15 CET  Auto-refresh snap "opera"
284  Done    today at 14:18 CET  today at 14:18 CET  Auto-refresh snap "firefox"
285  Done    today at 14:19 CET  today at 14:19 CET  Running service command for snap "onlyoffice-ds"
286  Done    today at 14:19 CET  today at 14:19 CET  Running service command for snap "onlyoffice-ds"
287  Done    today at 14:39 CET  today at 14:39 CET  Connect opera:wayland to snapd:wayland
288  Done    today at 15:53 CET  today at 15:55 CET  Install "beekeeper-studio" snap from "latest/stable" channel
289  Done    today at 15:58 CET  today at 15:58 CET  Remove "beekeeper-studio" snap
290  Done    today at 17:23 CET  today at 17:23 CET  Running service command for snap "onlyoffice-ds"
291  Done    today at 17:23 CET  today at 17:23 CET  Running service command for snap "onlyoffice-ds"
292  Done    today at 17:55 CET  today at 17:55 CET  Connect losslesscut:wayland to snapd:wayland
293  Done    today at 17:55 CET  today at 17:55 CET  Connect opera:wayland to snapd:wayland
294  Done    today at 17:55 CET  today at 17:55 CET  Connect opera:wayland to snapd:wayland
295  Done    today at 17:55 CET  today at 17:55 CET  Connect losslesscut:wayland to snapd:wayland
296  Done    today at 18:10 CET  today at 18:10 CET  Remove "losslesscut" snap
297  Done    today at 18:10 CET  today at 18:10 CET  Install "losslesscut" snap from "latest/stable" channel
298  Undo    today at 18:33 CET  -                   Remove "opera" snap
299  Done    today at 18:40 CET  today at 18:40 CET  Running service command for snap "onlyoffice-ds"
300  Done    today at 18:40 CET  today at 18:40 CET  Running service command for snap "onlyoffice-ds"
301  Done    today at 19:03 CET  today at 19:03 CET  Running service command for snap "onlyoffice-ds"
302  Done    today at 19:03 CET  today at 19:04 CET  Running service command for snap "onlyoffice-ds"

error: snap "opera" has "remove-snap" change in progress
 $  uzivatel@uzivatel  ~ 
**************************************************************************************
***************************************************************************************
sudo snap install opera
[sudo: authenticate] Password:
2025-11-26T20:53:23+01:00 INFO Waiting for automatic snapd restart...
error: cannot perform the following tasks:
- Mount snap "core22" (2163) (cannot proceed, expected snap "core22" revision 2163 to be mounted but is not)

*************************

 $  uzivatel@uzivatel  ~  sudo snap install opera
error: cannot perform the following tasks:
- Download snap "opera" (411) from channel "stable" (the download has been cancelled: context canceled)
- Mount snap "bare" (5) (cannot proceed, expected snap "bare" revision 5 to be mounted but is not)

********************
 $  uzivatel@uzivatel  ~  sudo systemctl status snapd
● snapd.service - Snap Daemon
     Loaded: loaded (/usr/lib/systemd/system/snapd.service; enabled; preset: enabled)
     Active: active (running) since Wed 2025-11-26 20:57:28 CET; 3min 58s ago
 Invocation: d33c7e4434a042b08592b1bcf8215094
TriggeredBy: ● snapd.socket
   Main PID: 6864 (snapd)
      Tasks: 15 (limit: 18872)
     Memory: 101.3M (peak: 108.6M)
        CPU: 9.676s
     CGroup: /system.slice/snapd.service
             └─6864 /usr/lib/snapd/snapd

nov 26 20:57:27 uzivatel snapd[6864]: backends.go:70: AppArmor status: apparmor is enabled and all features are available
nov 26 20:57:27 uzivatel snapd[6864]: backend.go:145: reloading profiles for snap-confine
nov 26 20:57:28 uzivatel systemd[1]: Started snapd.service - Snap Daemon.
nov 26 20:57:37 uzivatel snapd[6864]: api_snaps.go:536: Installing snap "opera" revision unset
nov 26 20:57:44 uzivatel snapd[6864]: handlers.go:1312: expected snap "bare" revision 5 to be mounted but is not
nov 26 20:57:54 uzivatel snapd[6864]: taskrunner.go:304: Change 5 task (Mount snap "bare" (5)) failed: cannot proceed, expected snap "bare" revision 5 to be mounted but is not
nov 26 20:57:54 uzivatel snapd[6864]: taskrunner.go:304: Change 5 task (Download snap "opera" (411) from channel "stable") failed: the download has been cancelled: context canceled
nov 26 20:59:15 uzivatel snapd[6864]: api_snaps.go:536: Installing snap "losslesscut" revision unset
nov 26 20:59:57 uzivatel snapd[6864]: handlers.go:1312: expected snap "core20" revision 2682 to be mounted but is not
nov 26 21:00:07 uzivatel snapd[6864]: taskrunner.go:304: Change 6 task (Mount snap "core20" (2682)) failed: cannot proceed, expected snap "core20" revision 2682 to be mounted but is not
 $  uzivatel@uzivatel  ~  losetup -a
/dev/loop0: []: (/var/lib/snapd/snaps/snapd_25577.snap)
 $  uzivatel@uzivatel  ~  sudo systemctl stop snapd
Stopping 'snapd.service', but its triggering units are still active:
snapd.socket
 $  uzivatel@uzivatel  ~  sudo systemctl start snapd
 $  uzivatel@uzivatel  ~  sudo snap install opera
error: cannot perform the following tasks:
- Mount snap "opera" (411) (cannot proceed, expected snap "opera" revision 411 to be mounted but is not)
- Mount snap "gtk-common-themes" (1535) (cannot proceed, expected snap "gtk-common-themes" revision 1535 to be mounted but is not)
- Mount snap "chromium-ffmpeg" (88) (cannot proceed, expected snap "chromium-ffmpeg" revision 88 to be mounted but is not)
- Mount snap "gnome-42-2204" (226) (cannot proceed, expected snap "gnome-42-2204" revision 226 to be mounted but is not)
 $  uzivatel@uzivatel  ~ 

******************************
Spätná väzba. Super. Tvoje rady mi pomohli. Opera je úspešne nainštalovaná

 $  uzivatel@uzivatel  ~  sudo snap install opera
error: cannot perform the following tasks:
- Mount snap "opera" (411) (cannot proceed, expected snap "opera" revision 411 to be mounted but is not)
- Mount snap "gtk-common-themes" (1535) (cannot proceed, expected snap "gtk-common-themes" revision 1535 to be mounted but is not)
- Mount snap "chromium-ffmpeg" (88) (cannot proceed, expected snap "chromium-ffmpeg" revision 88 to be mounted but is not)
- Mount snap "gnome-42-2204" (226) (cannot proceed, expected snap "gnome-42-2204" revision 226 to be mounted but is not)
 $  uzivatel@uzivatel  ~  sudo systemctl stop snapd.service snapd.socket
 $  uzivatel@uzivatel  ~  ps aux | grep snapd
uzivatel   15619  0.0  0.0  12020  2544 pts/1    S+   21:12   0:00 grep snapd
 $  uzivatel@uzivatel  ~  sudo systemctl start snapd.socket snapd.service
 $  uzivatel@uzivatel  ~  cd /var/lib/snapd/snaps
 $  uzivatel@uzivatel  /var/lib/snapd/snaps  ls -l | grep snap
-rw------- 2 root root     4096 Nov 26 21:02 bare_5.snap
-rw------- 2 root root 77545472 Nov 26 21:02 core22_2163.snap
-rw------- 2 root root 53399552 Nov 26 20:53 snapd_25577.snap
 $  uzivatel@uzivatel  /var/lib/snapd/snaps  sudo mount -o loop /var/lib/snapd/snaps/bare_5.snap /mnt
mount: /mnt: WARNING: source write-protected, mounted read-only.

 $  uzivatel@uzivatel  ~  sudo mount -o loop /var/lib/snapd/snaps/bare_5.snap /mnt
[sudo: authenticate] Password:
mount: /mnt: /var/lib/snapd/snaps/bare_5.snap is already mounted.
 $  uzivatel@uzivatel  ~  sudo snap install opera
opera 124.0.5705.42 from Opera (opera-software✓) installed
 $  uzivatel@uzivatel  ~ 

*************************************

 $  uzivatel@uzivatel  ~  sudo snap install losslesscut
[sudo: authenticate] Password:
error: cannot perform the following tasks:
- Mount snap "losslesscut" (139) (cannot proceed, expected snap "losslesscut" revision 139 to be mounted but is not)
- Mount snap "gnome-3-28-1804" (198) (cannot proceed, expected snap "gnome-3-28-1804" revision 198 to be mounted but is not)
 $  uzivatel@uzivatel  ~  ls -l | grep snap
drwx------  3 uzivatel uzivatel     3488 Nov 26 21:18 snap

**********************************

$  uzivatel@uzivatel  ~  sudo snap install firefox
[sudo: authenticate] Password:
error: cannot perform the following tasks:
- Mount snap "snapd" (25577) (cannot proceed, expected snap "snapd" revision 25577 to be mounted but is not)
$  uzivatel@uzivatel  ~  sudo snap install firefox
2025-11-26T22:10:21+01:00 INFO Waiting for automatic snapd restart...
error: cannot perform the following tasks:
- Mount snap "core22" (2163) (cannot proceed, expected snap "core22" revision 2163 to be mounted but is not)
$  uzivatel@uzivatel  ~  sudo systemctl stop snapd.service snapd.socket
$  uzivatel@uzivatel  ~  sudo systemctl start snapd.socket snapd.service
$  uzivatel@uzivatel  ~  ls -l /var/lib/snapd/snaps | grep
Použitie: grep [VOĽBA]... VZORY [SÚBOR]...
Ďalšie informácie získate príkazom „grep --help“.
$  uzivatel@uzivatel  ~  ls -l /var/lib/snapd/snaps | grep firefox
$  uzivatel@uzivatel  ~  FILE_NAME=$(ls /var/lib/snapd/snaps | grep 'firefox' | head -n 1)
$  uzivatel@uzivatel  ~  sudo mount -o loop "/var/lib/snapd/snaps/$FILE_NAME" /mnt
mount: /mnt: failed to setup loop device for /var/lib/snapd/snaps.
$  uzivatel@uzivatel  ~ 

************************

 $  uzivatel@uzivatel  ~  dmesg | grep loop
dmesg: read kernel buffer failed: Operácia nie je povolená
 $  uzivatel@uzivatel  ~  sudo dmesg | grep loop
[    0.109945] Calibrating delay loop (skipped), value calculated using timer frequency.. 5786.89 BogoMIPS (lpj=2893448)
[    0.291104] loop: module loaded
[    6.908593] loop0: detected capacity change from 0 to 8
[   87.013249] loop0: detected capacity change from 0 to 8

**********************

 $  uzivatel@uzivatel  ~  sudo dmesg | grep loop
[    0.109945] Calibrating delay loop (skipped), value calculated using timer frequency.. 5786.89 BogoMIPS (lpj=2893448)
[    0.291104] loop: module loaded
[    6.908593] loop0: detected capacity change from 0 to 8
[   87.013249] loop0: detected capacity change from 0 to 8
 $  uzivatel@uzivatel  ~  ls -l /var/lib/snapd/snaps/ | grep -E "snapd|core22|firefox"
 $  uzivatel@uzivatel  ~  sudo mkdir -p /mnt/snap-snapd /mnt/snap-core22
 $  uzivatel@uzivatel  ~  sudo mount -o loop /var/lib/snapd/snaps/snapd_25577.snap /mnt/snap-snapd
mount: /mnt/snap-snapd: failed to setup loop device for /var/lib/snapd/snaps/snapd_25577.snap.
 $  uzivatel@uzivatel  ~  sudo mount -o loop /var/lib/snapd/snaps/snapd_25577.snap /mnt/snap-snapd
mount: /mnt/snap-snapd: failed to setup loop device for /var/lib/snapd/snaps/snapd_25577.snap.
 $  uzivatel@uzivatel  ~  sudo snap install firefox
2025-11-26T22:33:43+01:00 INFO Waiting for automatic snapd restart...
error: cannot perform the following tasks:
- Download snap "firefox" (7423) from channel "stable" (the download has been cancelled: context canceled)
- Setup snap "snapd" (25577) security profiles (cannot get current snapd snap info: cannot find current revision for snap snapd: readlink /snap/snapd/current: no such file or directory)
- Mount snap "bare" (5) (cannot proceed, expected snap "bare" revision 5 to be mounted but is not)
 $  uzivatel@uzivatel  ~ 

*********************************