To avoid to have many packages to be removed you need to downgrade all the 9.3 packages.
~~~~~~~~~
First find them.
dpkg -l | grep 2.31-0ubuntu9.3
ii libc-bin 2.31-0ubuntu9.3 amd64 GNU C Library: Binaries
ii libc-dev-bin 2.31-0ubuntu9.3 amd64 GNU C Library: Development binaries
ii libc6:amd64 2.31-0ubuntu9.3 amd64 GNU C Library: Shared libraries
ii libc6-dbg:amd64 2.31-0ubuntu9.3 amd64 GNU C Library: detached debugging symbols
ii libc6-dev:amd64 2.31-0ubuntu9.3 amd64 GNU C Library: Development Libraries and Header Files
ii libc6-i386 2.31-0ubuntu9.3 amd64 GNU C Library: 32-bit shared libraries for AMD64
ii locales 2.31-0ubuntu9.3 all GNU C Library: National Language (locale) data [support]
To avoid to have many packages to be removed you need to downgrade all the 9.3 packages.
~~~~~~~~~
First find them.
dpkg -l | grep 2.31-0ubuntu9.3
ii libc-bin 2.31-0ubuntu9.3 amd64 GNU C Library: Binaries
ii libc-dev-bin 2.31-0ubuntu9.3 amd64 GNU C Library: Development binaries
ii libc6:amd64 2.31-0ubuntu9.3 amd64 GNU C Library: Shared libraries
ii libc6-dbg:amd64 2.31-0ubuntu9.3 amd64 GNU C Library: detached debugging symbols
ii libc6-dev:amd64 2.31-0ubuntu9.3 amd64 GNU C Library: Development Libraries and Header Files
ii libc6-i386 2.31-0ubuntu9.3 amd64 GNU C Library: 32-bit shared libraries for AMD64
ii locales 2.31-0ubuntu9.3 all GNU C Library: National Language (locale) data [support]
~~~~~~~~~
Then downgrade them all.
sudo apt install libc-bin= 2.31-0ubuntu9. 2 libc-dev- bin=2.31- 0ubuntu9. 2 libc6:amd64= 2.31-0ubuntu9. 2 libc6-dbg: amd64=2. 31-0ubuntu9. 2 libc6-dev: amd64=2. 31-0ubuntu9. 2 libc6-i386= 2.31-0ubuntu9. 2 locales= 2.31-0ubuntu9. 2
Lecture des listes de paquets... Fait 20.04/focal- updates [amd64]) [] 20.04/focal- updates [amd64]) [] 20.04/focal- updates [amd64]) [] 20.04/focal- updates [amd64]) [] 20.04/focal- updates [amd64]) 20.04/focal- updates [amd64]) 20.04/focal- updates [all]) 20.04/focal- updates [amd64]) 20.04/focal- updates [amd64]) 20.04/focal- updates [amd64]) 20.04/focal- updates [amd64]) 20.04/focal- updates [amd64]) 20.04/focal- updates [amd64]) 20.04/focal- updates [all])
Construction de l'arbre des dépendances
Lecture des informations d'état... Fait
Paquets suggérés :
glibc-doc
Les paquets suivants seront mis à une VERSION INFÉRIEURE :
libc-bin libc-dev-bin libc6 libc6-dbg libc6-dev libc6-i386 locales
0 mis à jour, 0 nouvellement installés, 7 remis à une version inférieure, 0 à enlever et 0 non mis à jour.
Inst libc6-dbg [2.31-0ubuntu9.3] (2.31-0ubuntu9.2 Ubuntu:
Inst libc6-i386 [2.31-0ubuntu9.3] (2.31-0ubuntu9.2 Ubuntu:
Inst libc6-dev [2.31-0ubuntu9.3] (2.31-0ubuntu9.2 Ubuntu:
Inst libc-dev-bin [2.31-0ubuntu9.3] (2.31-0ubuntu9.2 Ubuntu:
Inst libc6 [2.31-0ubuntu9.3] (2.31-0ubuntu9.2 Ubuntu:
Conf libc6 (2.31-0ubuntu9.2 Ubuntu:
Inst locales [2.31-0ubuntu9.3] (2.31-0ubuntu9.2 Ubuntu:
Inst libc-bin [2.31-0ubuntu9.3] (2.31-0ubuntu9.2 Ubuntu:
Conf libc-bin (2.31-0ubuntu9.2 Ubuntu:
Conf libc6-dbg (2.31-0ubuntu9.2 Ubuntu:
Conf libc6-i386 (2.31-0ubuntu9.2 Ubuntu:
Conf libc6-dev (2.31-0ubuntu9.2 Ubuntu:
Conf libc-dev-bin (2.31-0ubuntu9.2 Ubuntu:
Conf locales (2.31-0ubuntu9.2 Ubuntu: