Source ID was not found when attempting to remove it

[Clinton H]

1) Ubuntu 19.10
2) Files 1:3.34.1-1ubuntu1
3) I clicked on a folder in Nautilus, a busy indicator was displayed for several minutes, instead of the folder contents. I clicked the back arrow and then clicked the same folder again. The folder contents displayed immediately. I decided to run Nautilus from the terminal. This error and some other errors were displayed in the terminal output.
4) Error in terminal.

[Andre Klapper (a9016009)]

Clinton H: Please see https://gitlab.gnome.org/GNOME/gdm/issues/547#note_673701 which information to provide.

[Clinton H (49studebaker)]

I have the gdb package installed, but I can not find the gdm debug and glib2 debug packages in Synaptic package manager. How do I install those packages?