Merci pour avoir répondu si rapidement !
Voilà le résultat :
~$ cat /etc/apt/sources.list
# deb cdrom:[Ubuntu 18.04.1 LTS _Bionic Beaver_ - Release amd64 (20180725)]/ bionic main restricted
# See http://help.ubuntu.com/community/UpgradeNotes for how to upgrade to
# newer versions of the distribution.
deb http://fr.archive.ubuntu.com/ubuntu/ focal main restricted
# deb-src http://fr.archive.ubuntu.com/ubuntu/ bionic main restricted
## Major bug fix updates produced after the final release of the
## distribution.
deb http://fr.archive.ubuntu.com/ubuntu/ focal-updates main restricted
# deb-src http://fr.archive.ubuntu.com/ubuntu/ bionic-updates main restricted
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team. Also, please note that software in universe WILL NOT receive any
## review or updates from the Ubuntu security team.
deb http://fr.archive.ubuntu.com/ubuntu/ focal universe
# deb-src http://fr.archive.ubuntu.com/ubuntu/ bionic universe
deb http://fr.archive.ubuntu.com/ubuntu/ focal-updates universe
# deb-src http://fr.archive.ubuntu.com/ubuntu/ bionic-updates universe
## N.B. software from this repository is ENTIRELY UNSUPPORTED by the Ubuntu
## team, and may not be under a free licence. Please satisfy yourself as to
## your rights to use the software. Also, please note that software in
## multiverse WILL NOT receive any review or updates from the Ubuntu
## security team.
deb http://fr.archive.ubuntu.com/ubuntu/ focal multiverse
# deb-src http://fr.archive.ubuntu.com/ubuntu/ bionic multiverse
deb http://fr.archive.ubuntu.com/ubuntu/ focal-updates multiverse
# deb-src http://fr.archive.ubuntu.com/ubuntu/ bionic-updates multiverse
## N.B. software from this repository may not have been tested as
## extensively as that contained in the main release, although it includes
## newer versions of some applications which may provide useful features.
## Also, please note that software in backports WILL NOT receive any review
## or updates from the Ubuntu security team.
deb http://fr.archive.ubuntu.com/ubuntu/ focal-backports main restricted universe multiverse
# deb-src http://fr.archive.ubuntu.com/ubuntu/ bionic-backports main restricted universe multiverse
## Uncomment the following two lines to add software from Canonical's
## 'partner' repository.
## This software is not part of Ubuntu, but is offered by Canonical and the
## respective vendors as a service to Ubuntu users.
deb http://archive.canonical.com/ubuntu focal partner
# deb-src http://archive.canonical.com/ubuntu bionic partner
deb http://security.ubuntu.com/ubuntu focal-security main restricted
# deb-src http://security.ubuntu.com/ubuntu bionic-security main restricted
deb http://security.ubuntu.com/ubuntu focal-security universe
# deb-src http://security.ubuntu.com/ubuntu bionic-security universe
deb http://security.ubuntu.com/ubuntu focal-security multiverse
# deb-src http://security.ubuntu.com/ubuntu bionic-security multiverse
~$ ls /etc/apt/sources.list.d
deadsnakes-ubuntu-ppa-bionic.list git-core-ubuntu-ppa-bionic.list google-chrome.list.save skype-stable.list.distUpgrade
deadsnakes-ubuntu-ppa-bionic.list.distUpgrade git-core-ubuntu-ppa-bionic.list.distUpgrade otto-kesselgulasch-ubuntu-gimp-bionic.list skype-stable.list.save
freecad-maintainers-ubuntu-freecad-stable-bionic.list git-core-ubuntu-ppa-bionic.list.save otto-kesselgulasch-ubuntu-gimp-bionic.list.distUpgrade teams.list
freecad-maintainers-ubuntu-freecad-stable-bionic.list.distUpgrade google-chrome.list otto-kesselgulasch-ubuntu-gimp-bionic.list.save teams.list.distUpgrade
freecad-maintainers-ubuntu-freecad-stable-bionic.list.save google-chrome.list.distUpgrade skype-stable.list teams.list.save
~$ cat /etc/apt/sources.list.d/*.list
# deb http://ppa.launchpad.net/deadsnakes/ppa/ubuntu focal main # désactivé pour la mise à niveau vers focal
# deb-src http://ppa.launchpad.net/deadsnakes/ppa/ubuntu bionic main
# deb http://ppa.launchpad.net/freecad-maintainers/freecad-stable/ubuntu focal main # désactivé pour la mise à niveau vers focal
# deb-src http://ppa.launchpad.net/freecad-maintainers/freecad-stable/ubuntu bionic main
# deb http://ppa.launchpad.net/git-core/ppa/ubuntu focal main # désactivé pour la mise à niveau vers focal
# deb-src http://ppa.launchpad.net/git-core/ppa/ubuntu bionic main
### THIS FILE IS AUTOMATICALLY CONFIGURED ###
# You may comment out this entry, but any other modifications may be lost.
# deb [arch=amd64] http://dl.google.com/linux/chrome/deb/ stable main # désactivé pour la mise à niveau vers focal
# deb http://ppa.launchpad.net/otto-kesselgulasch/gimp/ubuntu focal main # désactivé pour la mise à niveau vers focal
# deb-src http://ppa.launchpad.net/otto-kesselgulasch/gimp/ubuntu bionic main
# deb [arch=amd64] https://repo.skype.com/deb stable main # désactivé pour la mise à niveau vers focal
### THIS FILE IS AUTOMATICALLY CONFIGURED ###
# You may comment out this entry, but any other modifications may be lost.
# deb [arch=amd64] https://packages.microsoft.com/repos/ms-teams stable main # désactivé pour la mise à niveau vers focal
~$ apt list | grep "installé, local"
WARNING: apt does not have a stable CLI interface. Use with caution in scripts.
command-not-found-data/now 18.04.5 amd64 [installé, local]
gir1.2-mutter-2/now 3.28.4-0ubuntu18.04.2 amd64 [installé, local]
git-man/now 1:2.29.2-0ppa1~ubuntu18.04.1 all [installé, local]
git/now 1:2.29.2-0ppa1~ubuntu18.04.1 amd64 [installé, local]
google-chrome-stable/now 87.0.4280.88-1 amd64 [installé, local]
libbind9-160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installé, local]
libboost-date-time1.65.1/now 1.65.1+dfsg-0ubuntu5 amd64 [installé, local]
libboost-filesystem1.65.1/now 1.65.1+dfsg-0ubuntu5 amd64 [installé, local]
libboost-iostreams1.65.1/now 1.65.1+dfsg-0ubuntu5 amd64 [installé, local]
libboost-locale1.65.1/now 1.65.1+dfsg-0ubuntu5 amd64 [installé, local]
libboost-system1.65.1/now 1.65.1+dfsg-0ubuntu5 amd64 [installé, local]
libboost-thread1.65.1/now 1.65.1+dfsg-0ubuntu5 amd64 [installé, local]
libbrlapi0.6/now 5.5-4ubuntu2.0.1 amd64 [installé, local]
libcamel-1.2-61/now 3.28.5-0ubuntu0.18.04.3 amd64 [installé, local]
libcdio17/now 1.0.0-2ubuntu2 amd64 [installé, local]
libdns-export1100/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installé, local]
libdns1100/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installé, local]
libebook-contacts-1.2-2/now 3.28.5-0ubuntu0.18.04.3 amd64 [installé, local]
libecal-1.2-19/now 3.28.5-0ubuntu0.18.04.3 amd64 [installé, local]
libedataserver-1.2-23/now 3.28.5-0ubuntu0.18.04.3 amd64 [installé, local]
libevent-2.1-6/now 2.1.8-stable-4build1 amd64 [installé, local]
libexempi3/now 2.4.5-2 amd64 [installé, local]
libexiv2-14/now 0.25-3.1ubuntu0.18.04.5 amd64 [installé, local]
libffi6/now 3.2.1-8 amd64 [installé, local]
libgdbm5/now 1.14.1-6 amd64 [installé, local]
libgnome-desktop-3-17/now 3.28.2-0ubuntu1.5 amd64 [installé, local]
libgspell-1-1/now 1.6.1-1 amd64 [installé, local]
libgutenprint2/now 5.2.13-2 amd64 [installé, local]
libgweather-3-15/now 3.28.2-1~ubuntu18.04.1 amd64 [installé, local]
libhogweed4/now 3.4-1 amd64 [installé, local]
libhunspell-1.6-0/now 1.6.2-1 amd64 [installé, local]
libicu60/now 60.2-3ubuntu3.1 amd64 [installé, local]
libilmbase12/now 2.2.0-11ubuntu2 amd64 [installé, local]
libip4tc0/now 1.6.1-2ubuntu2 amd64 [installé, local]
libip6tc0/now 1.6.1-2ubuntu2 amd64 [installé, local]
libirs160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installé, local]
libisc-export169/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installé, local]
libisc169/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installé, local]
libisccc160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installé, local]
libisccfg160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installé, local]
libisl19/now 0.19-1 amd64 [installé, local]
libjson-c3/now 0.12.1-1.3ubuntu0.3 amd64 [installé, local]
libldb1/now 2:1.2.3-1ubuntu0.1 amd64 [installé, local]
liblouis14/now 3.5.0-1ubuntu0.3 amd64 [installé, local]
liblouisutdml8/now 2.7.0-1 amd64 [installé, local]
liblwres160/now 1:9.11.3+dfsg-1ubuntu1.13 amd64 [installé, local]
libmagickcore-6.q16-3-extra/now 8:6.9.7.4+dfsg-16ubuntu6.8 amd64 [installé, local]
libmagickcore-6.q16-3/now 8:6.9.7.4+dfsg-16ubuntu6.8 amd64 [installé, local]
libmagickwand-6.q16-3/now 8:6.9.7.4+dfsg-16ubuntu6.8 amd64 [installé, local]
libminiupnpc10/now 1.9.20140610-4ubuntu2 amd64 [installé, local]
libmutter-2-0/now 3.28.4-0ubuntu18.04.2 amd64 [installé, local]
libnettle6/now 3.4-1 amd64 [installé, local]
libnih1/now 1.0.3-6ubuntu2 amd64 [installé, local]
libntfs-3g88/now 1:2017.3.23-2ubuntu0.18.04.2 amd64 [installé, local]
libopenexr22/now 2.2.0-11.1ubuntu1.3 amd64 [installé, local]
liborcus-0.13-0/now 0.13.4-2 amd64 [installé, local]
libperl5.26/now 5.26.1-6ubuntu0.5 amd64 [installé, local]
libplymouth4/now 0.9.3-1ubuntu7.18.04.2 amd64 [installé, local]
libpoppler73/now 0.62.0-2ubuntu2.12 amd64 [installé, local]
libprocps6/now 2:3.3.12-3ubuntu1.2 amd64 [installé, local]
libprotobuf10/now 3.0.0-9.1ubuntu1 amd64 [installé, local]
libpython3.6-minimal/now 3.6.9-1~18.04ubuntu1.3 amd64 [installé, local]
libpython3.6-stdlib/now 3.6.9-1~18.04ubuntu1.3 amd64 [installé, local]
libpython3.6/now 3.6.9-1~18.04ubuntu1.3 amd64 [installé, local]
libpython3.7-minimal/now 3.7.9-1+bionic1 amd64 [installé, local]
libpython3.7-stdlib/now 3.7.9-1+bionic1 amd64 [installé, local]
libpython3.8-minimal/now 3.8.6-1+bionic2 amd64 [installé, local]
libpython3.8-stdlib/now 3.8.6-1+bionic2 amd64 [installé, local]
libqpdf21/now 8.0.2-3 amd64 [installé, local]
libraw16/now 0.18.8-1ubuntu0.3 amd64 [installé, local]
libreadline7/now 7.0-3 amd64 [installé, local]
libsndio6.1/now 1.1.0-3 amd64 [installé, local]
libssl1.0.0/now 1.0.2n-1ubuntu5.4 amd64 [installé, local]
libusbmuxd4/now 1.1.0~git20171206.c724e70f-0.1 amd64 [installé, local]
libvpx5/now 1.7.0-3ubuntu0.18.04.1 amd64 [installé, local]
linux-signed-generic/now 4.15.0.126.113 amd64 [installé, local]
multiarch-support/now 2.27-3ubuntu1.3 amd64 [installé, local]
nplan/now 0.99-0ubuntu3~18.04.3 all [installé, local]
perl-modules-5.26/now 5.26.1-6ubuntu0.5 all [installé, local]
pidgin-libnotify/now 0.14-9ubuntu2 amd64 [installé, local]
postgresql-10/now 10.15-0ubuntu0.18.04.1 amd64 [installé, local]
postgresql-client-10/now 10.15-0ubuntu0.18.04.1 amd64 [installé, local]
python-talloc/now 2.1.10-2ubuntu1 amd64 [installé, local]
python3.6-minimal/now 3.6.9-1~18.04ubuntu1.3 amd64 [installé, local]
python3.6-venv/now 3.6.9-1~18.04ubuntu1.3 amd64 [installé, local]
python3.6/now 3.6.9-1~18.04ubuntu1.3 amd64 [installé, local]
python3.7-minimal/now 3.7.9-1+bionic1 amd64 [installé, local]
python3.7/now 3.7.9-1+bionic1 amd64 [installé, local]
python3.8-minimal/now 3.8.6-1+bionic2 amd64 [installé, local]
python3.8-venv/now 3.8.6-1+bionic2 amd64 [installé, local]
python3.8/now 3.8.6-1+bionic2 amd64 [installé, local]
skypeforlinux/now 8.66.0.74 amd64 [installé, local]
teams/now 1.3.00.30857 amd64 [installé, local]
ubuntu-web-launchers/now 18.04.7 all [installé, local]
ureadahead/now 0.100.0-21 amd64 [installé, local]
zoom/now 5.0.413237.0524 amd64 [installé, local]