Bonsoir, je met un peut de temps à répondre mais d'une vous remercie de l'intérêt porté à ma question et deux suis toujours motivé pour la résoudre.
J'ai donc suivi le premier protocole proposé voici ce qui en ressort.
verger@verger-MS-7B84:~$ find /etc/apt -name '*.list' -exec bash -c 'echo -e "\n$1\n"; nl -ba "$1"' _ '{}' \;
/etc/apt/sources.list
1 # deb cdrom:[Ubuntu 20.04 LTS _Focal Fossa_ - Release amd64 (20200423)]/ focal main restricted
2
3 # See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
4 # newer versions of the distribution.
5 deb http://fr.archive.ubuntu.com/ubuntu/ focal main restricted
6 # deb-src http://fr.archive.ubuntu.com/ubuntu/ focal main restricted
7
8 ## Major bug fix updates produced after the final release of the
9 ## distribution.
10 deb http://fr.archive.ubuntu.com/ubuntu/ focal-updates main restricted
11 # deb-src http://fr.archive.ubuntu.com/ubuntu/ focal-updates main restricted
12
13 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
14 ## team. Also, please note that software in universe WILL NOT receive any
15 ## review or updates from the Ubuntu security team.
16 deb http://fr.archive.ubuntu.com/ubuntu/ focal universe
17 # deb-src http://fr.archive.ubuntu.com/ubuntu/ focal universe
18 deb http://fr.archive.ubuntu.com/ubuntu/ focal-updates universe
19 # deb-src http://fr.archive.ubuntu.com/ubuntu/ focal-updates universe
20
21 ## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
22 ## team, and may not be under a free licence. Please satisfy yourself as to
23 ## your rights to use the software. Also, please note that software in
24 ## multiverse WILL NOT receive any review or updates from the Ubuntu
25 ## security team.
26 deb http://fr.archive.ubuntu.com/ubuntu/ focal multiverse
27 # deb-src http://fr.archive.ubuntu.com/ubuntu/ focal multiverse
28 deb http://fr.archive.ubuntu.com/ubuntu/ focal-updates multiverse
29 # deb-src http://fr.archive.ubuntu.com/ubuntu/ focal-updates multiverse
30
31 ## N.B. software from this repository may not have been tested as
32 ## extensively as that contained in the main release, although it includes
33 ## newer versions of some applications which may provide useful features.
34 ## Also, please note that software in backports WILL NOT receive any review
35 ## or updates from the Ubuntu security team.
36 deb http://fr.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
37 # deb-src http://fr.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
38
39 ## Uncomment the following two lines to add software from Canonical's
40 ## 'partner' repository.
41 ## This software is not part of Ubuntu, but is offered by Canonical and the
42 ## respective vendors as a service to Ubuntu users.
43 # deb http://archive.canonical.com/ubuntu focal partner
44 # deb-src http://archive.canonical.com/ubuntu focal partner
45
46 deb http://security.ubuntu.com/ubuntu focal-security main restricted
47 # deb-src http://security.ubuntu.com/ubuntu focal-security main restricted
48 deb http://security.ubuntu.com/ubuntu focal-security universe
49 # deb-src http://security.ubuntu.com/ubuntu focal-security universe
50 deb http://security.ubuntu.com/ubuntu focal-security multiverse
51 # deb-src http://security.ubuntu.com/ubuntu focal-security multiverse
52
53 # This system was installed using small removable media
54 # (e.g. netinst, live or single CD). The matching "deb cdrom"
55 # entries were disabled at the end of the installation process.
56 # For information about how to configure apt package sources,
57 # see the sources.list(5) manual.
58 deb https://dl.winehq.org/wine-builds/ubuntu/ focal main
59 # deb-src https://dl.winehq.org/wine-builds/ubuntu/ focal main
60 deb https://dl.winehq.org/wine-builds/ubuntu/ focalmain
61 # deb-src https://dl.winehq.org/wine-builds/ubuntu/ focalmain
/etc/apt/sources.list.d/openmw-ubuntu-openmw-focal.list
1 deb http://ppa.launchpad.net/openmw/openmw/ubuntu focal main
2 # deb-src http://ppa.launchpad.net/openmw/openmw/ubuntu focal main
verger@verger-MS-7B84:~$