Interestingly, I can reproduce this; but when I tried to debug it (by running python3 /usr/lib/software-properties/software-properties-dbus manually from a root shell and watching its output), the bug was no longer reproducible. This pointed to a problem specific to the process environment - and indeed, if I run software-properties-dbus with LANG=C, I get the following error (repeatedly):
WARNING:root:could not open file '/etc/apt/sources.list'
This points to a bug in aptsources.sourceslist.SourcesList.load(), which is using the default encoding (ascii) when opening the file for reading.
Interestingly, I can reproduce this; but when I tried to debug it (by running python3 /usr/lib/ software- properties/ software- properties- dbus manually from a root shell and watching its output), the bug was no longer reproducible. This pointed to a problem specific to the process environment - and indeed, if I run software- properties- dbus with LANG=C, I get the following error (repeatedly):
WARNING:root:could not open file '/etc/apt/ sources. list'
This points to a bug in aptsources. sourceslist. SourcesList. load(), which is using the default encoding (ascii) when opening the file for reading.