Fail in upgrade to 21.04

[chantal]

can't upgrade to 21.0
get the message :
"An unresolvable problem occurred while calculating the upgrade.

 If none of this applies, then please report this bug using the command 'ubuntu-bug ubuntu-release-upgrader-core' in a terminal. If you want to investigate this yourself the log files in '/var/log/dist-upgrade' will contain details about the upgrade. Specifically, look at 'main.log' and 'apt.log'."

Here main.log file : https://drop.chapril.org/download/d15a3cd196d96a89/#CYJTk1SqlvRjG4fbY0-BWw (expires after 5 days)
Here apt.log file : https://drop.chapril.org/download/b7f475dce91d38d9/#C9r_ueZLtQdavrvdbvykHA
(expires after 5 days)

Thank for your help !

ProblemType: Bug
DistroRelease: Ubuntu 20.10
Package: ubuntu-release-upgrader-core 1:20.10.15
ProcVersionSignature: Ubuntu 5.8.0-53.60-generic 5.8.18
Uname: Linux 5.8.0-53-generic x86_64
ApportVersion: 2.20.11-0ubuntu50.6
Architecture: amd64
CasperMD5CheckResult: skip
CrashDB: ubuntu
CurrentDesktop: ubuntu:GNOME
Date: Fri May 14 09:53:19 2021
InstallationDate: Installed on 2021-02-03 (99 days ago)
InstallationMedia: Ubuntu 20.04.1 LTS "Focal Fossa" - Release amd64 (20200731)
PackageArchitecture: all
SourcePackage: ubuntu-release-upgrader
UpgradeStatus: Upgraded to groovy on 2021-05-14 (0 days ago)
VarLogDistupgradeAptlog:
 Log time: 2021-05-14 09:51:30.696117
 Log time: 2021-05-14 09:51:36.462482
VarLogDistupgradeTermlog:

[Brian Murray (brian-murray)]

Could you please add the /var/log/dist-upgrade/apt.log file from your upgrade attempt to the bug report as an attachment? Thanks in advance.

[chantal (frenchredfrog)]

/var/log/dist-upgrade/apt.log file : https://drop.infini.fr/r/C7X0J6JTqr#Iy6UBAya4aJ4GOX/k3xszribWC3dS7LrQZOa4MKlN9Q=

[chantal (frenchredfrog)]

Thanks.
Added as a comment !
https://drop.infini.fr/r/C7X0J6JTqr#Iy6UBAya4aJ4GOX/k3xszribWC3dS7LrQZOa4MKlN9Q=

On 21/05/2021 01:15, Brian Murray wrote:
> /var/log/dist-upgrade/apt.log file

[Launchpad Janitor (janitor)]

[Expired for ubuntu-release-upgrader (Ubuntu) because there has been no activity for 60 days.]

[nick touran (7hgg)]

I'm seeing the same thing and am having trouble deciphering the real problem from the log (attached).