The software is not able to calculate how much space there is left for the advancement to ubunto 23.10

[Bruno]

<pre><span style="color:#26A269"><b>bruno@bruno-VPCEL2S1E</b></span>:<span style="color:#12488B"><b>~</b></span>$ ubuntu-bug ubuntu-release-upgrader-core
<span style="color:#26A269"><b>bruno@bruno-VPCEL2S1E</b></span>:<span style="color:#12488B"><b>~</b></span>$ update.go:85: cannot change mount namespace according to change mount (/var/lib/snapd/hostfs/usr/share/gimp/2.0/help /usr/share/gimp/2.0/help none bind,ro 0 0): cannot open directory &quot;/var/lib&quot;: permission denied
update.go:85: cannot change mount namespace according to change mount (/var/lib/snapd/hostfs/usr/share/xubuntu-docs /usr/share/xubuntu-docs none bind,ro 0 0): cannot open directory &quot;/var/lib&quot;: permission denied
Gtk-<span style="color:#26A269"><b>Message</b></span>: <span style="color:#12488B">11:36:24.176</span>: Not loading module &quot;atk-bridge&quot;: The functionality is provided by GTK natively. Please try to not load it.

(firefox:6875): Gtk-<span style="color:#A2734C"><b>WARNING</b></span> **: <span style="color:#12488B">11:36:24.775</span>: GTK+ module /snap/firefox/3358/gnome-platform/usr/lib/gtk-2.0/modules/libcanberra-gtk-module.so cannot be loaded.
GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported.
Gtk-<span style="color:#26A269"><b>Message</b></span>: <span style="color:#12488B">11:36:24.775</span>: Failed to load module &quot;canberra-gtk-module&quot;

(firefox:6875): Gtk-<span style="color:#A2734C"><b>WARNING</b></span> **: <span style="color:#12488B">11:36:24.789</span>: GTK+ module /snap/firefox/3358/gnome-platform/usr/lib/gtk-2.0/modules/libcanberra-gtk-module.so cannot be loaded.
GTK+ 2.x symbols detected. Using GTK+ 2.x and GTK+ 3 in the same process is not supported.
Gtk-<span style="color:#26A269"><b>Message</b></span>: <span style="color:#12488B">11:36:24.789</span>: Failed to load module &quot;canberra-gtk-module&quot;
ATTENTION: default value of option mesa_glthread overridden by environment.
ATTENTION: default value of option mesa_glthread overridden by environment.
</pre>

ProblemType: Bug
DistroRelease: Ubuntu 23.04
Package: ubuntu-release-upgrader-core 1:23.04.7
ProcVersionSignature: Ubuntu 6.2.0-39.40-generic 6.2.16
Uname: Linux 6.2.0-39-generic x86_64
ApportVersion: 2.26.1-0ubuntu2.1
Architecture: amd64
CasperMD5CheckResult: unknown
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Thu Dec 21 11:33:40 2023
InstallationDate: Installed on 2020-05-05 (1324 days ago)
InstallationMedia: Ubuntu 20.04 LTS "Focal Fossa" - Release amd64 (20200423)
PackageArchitecture: all
ProcEnviron:
 LANG=it_IT.UTF-8
 PATH=(custom, no user)
 SHELL=/bin/bash
 TERM=xterm-256color
 XDG_RUNTIME_DIR=<set>
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to lunar on 2023-12-21 (0 days ago)
VarLogDistupgradeTermlog:

mtime.conffile..etc.update-manager.release-upgrades: 2023-04-26T18:46:37.012133