I’m doing a remote upgrade from 18.04 LTS to 20.4 LTS over ssh, trying to follow this recipe:
https://ostechnix.com/how-to-upgrade-to-ubuntu-20-04-lts-server/
However, it seems the upgrade stopped while cleaning up the packages — it detached from screen and never got to the “System upgrade complete” message. Running sudo do-release-upgrade -d again says “There is no development version of an LTS available”. Since this is remote, I’m afraid to reboot or do the wrong thing. How can I check/resume/fix the upgrade?
Here’s the last part of the /var/log/dist-upgrade/…/main.log:
2020-09-26 10:20:41,799 ERROR not handled exception:
Traceback (most recent call last):
File "/tmp/ubuntu-release-upgrader-soxxvnbe/DistUpgrade/DistUpgradeCache.py",
line 997, in tryMarkObsoleteForRemoval
self.restore_snapshot()
File "/tmp/ubuntu-release-upgrader-soxxvnbe/DistUpgrade/DistUpgradeCache.py",
line 370, in restore_snapshot
pkg.mark_delete()
File "/usr/lib/python3/dist-packages/apt/package.py", line 1509, in mark_delete
apt_pkg.Error: E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.
During handling of the above exception, another exception occurred:
Traceback (most recent call last):
File "/tmp/ubuntu-release-upgrader-soxxvnbe/focal", line 8, in <module>
sys.exit(main())
File "/tmp/ubuntu-release-upgrader-soxxvnbe/DistUpgrade/DistUpgradeMain.py", line 238, in main
if app.run():
File "/tmp/ubuntu-release-upgrader-soxxvnbe/DistUpgrade/DistUpgradeController.py", line 2081, in run
return self.fullUpgrade()
File "/tmp/ubuntu-release-upgrader-soxxvnbe/DistUpgrade/DistUpgradeController.py", line 2058, in fullUpgrade
self.doPostUpgrade()
File "/tmp/ubuntu-release-upgrader-soxxvnbe/DistUpgrade/DistUpgradeController.py", line 1484, in doPostUpgrade
if not self.cache.tryMarkObsoleteForRemoval(pkgname, remove_candidates, self.forced_obsoletes, self.foreign_pkgs):
File "/tmp/ubuntu-release-upgrader-soxxvnbe/DistUpgrade/DistUpgradeCache.py", line 243, in wrapper
res = f(*args, **kwargs)
File "/tmp/ubuntu-release-upgrader-soxxvnbe/DistUpgrade/DistUpgradeCache.py", line 1001, in tryMarkObsoleteForRemoval
self.restore_snapshot()
File "/tmp/ubuntu-release-upgrader-soxxvnbe/DistUpgrade/DistUpgradeCache.py", line 370, in restore_snapshot
pkg.mark_delete()
File "/usr/lib/python3/dist-packages/apt/package.py", line 1509, in mark_delete
apt_pkg.Error: E:Error, pkgProblemResolver::Resolve generated breaks, this may be caused by held packages.