Thanks Jean-Baptiste for the analysis of the issue. This is indeed a bug in the release-upgrader.
@roberto: as a workaround you can run "sudo apt-get install grep:amd64" and then re-run the upgrade again.
Thanks Jean-Baptiste for the analysis of the issue. This is indeed a bug in the release-upgrader.
@roberto: as a workaround you can run "sudo apt-get install grep:amd64" and then re-run the upgrade again.