Ubuntu 9.10 to 10.04: worst upgrade experience ever.

I'm used to smooth upgrades of both single packages and full distributions, with Debian and Ubuntu. Not so for this upgrade from 9.10 to 10.04. I'll sum up the failures I encountered and my suggested fixes:

  • after upgrading+rebooting, your native IPv6 is suddenly replaced by a freenet tunnel. Cause: you installed gw6c on 9.10 which came with no configuration; 10.04 updated the configuration to automatically use freenet. Fix: remove gw6c package.
  • you're using the excellent dovecot-postfix package, and after the upgrade, no mail comes in. Cause: cmusieve is gone. Fix: change dovecot config to use sieve.
  • lighttpd will not start, complaining about port 80. Cause: lighttpd ipv6 is basically broken in 10.04. Known issue, not fixed. Fix: add server.use-ipv6="enable" to lighttpd.conf
  • dovecot is not listening on v6 anymore. Cause: the upgrade messed up your listen directives. Fix: add listen = *, [::] to dovecot.conf

Extra free tip: get rid of some old kernels, they tend to eat a lot of diskspace with their modules.