Failure to install chromium-browser/chromium snap

[Thomas Schwinge]

On an up-to-date Ubuntu 20.04 system, I can't 'sudo apt install chromium-browser':

    Reading package lists... Done
    Building dependency tree
    Reading state information... Done
    The following NEW packages will be installed:
      chromium-browser
    0 upgraded, 1 newly installed, 0 to remove and 3 not upgraded.
    Need to get 0 B/48.3 kB of archives.
    After this operation, 164 kB of additional disk space will be used.
    Preconfiguring packages ...
    (Reading database ... 293039 files and directories currently installed.)
    Preparing to unpack .../chromium-browser_1%3a85.0.4183.83-0ubuntu0.20.04.2_amd64.deb ...
    => Installing the chromium snap
    ==> Checking connectivity with the snap store
    ==> Installing the chromium snap
    Fehler: cannot perform the following tasks:
    - Den Konfigurationshook von Snap "chromium" ausführen, falls vorhanden (run hook "configure": cannot perform operation: mount --rbind /home /tmp/snap.rootfs_PJbiPg//home: Permission denied)
    dpkg: error processing archive /var/cache/apt/archives/chromium-browser_1%3a85.0.4183.83-0ubuntu0.20.04.2_amd64.deb (--unpack):
     new chromium-browser package pre-installation script subprocess returned error exit status 1
    Errors were encountered while processing:
     /var/cache/apt/archives/chromium-browser_1%3a85.0.4183.83-0ubuntu0.20.04.2_amd64.deb
    E: Sub-process /usr/bin/dpkg returned an error code (1)

Might that 'mount' command have an issue with my '/home -> media/galvani/francesco/home' symlink? (But that has not been a problem in the previous Ubuntu 18.04 installation, where I'm reasonably sure that I did have a snap or two installed, too.)

[Olivier Tilloy (osomon)]

Yes, your symlink is very likely the cause of this error.
You weren't seeing the problem in 18.04 because chromium was a a real deb package there, whereas starting with 20.04 it is packaged as a snap.

This is not chromium-specific, all snaps would fail to install with such a setup.

One possible workaround would be to bind mount /media/galvani/francesco/home to /home instead of using a symlink.