Dear Brian, Thank you very much for your support. I don't know how you found it, but yes, this was the problem. I need to install pa-purge and execute: ppa-purge ubuntu-toolchain-r/test
I did not remember having that: many packages related with g++ where downgraded and then the system upgrade to 18.04 worked perfectly. Best, Kin M. -- You received this bug notification because you are a member of Ubuntu Bugs, which is subscribed to Ubuntu. https://bugs.launchpad.net/bugs/1791150 Title: cannot upgrade from previous stable version. Myabe I have " Unofficial software packages not provided by Ubuntu" To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/ubuntu-release-upgrader/+bug/1791150/+subscriptions -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
