The community wiki currently claims that the default editor for visudo has been sensible-editor since 8.10 [1]. But for me in both 12.04 and 14.04, `sudo visudo` still launches /etc/alternatives/editor, so select-editor doesn’t actually change visudo’s editor; for that I have to run `sudo update-alternatives –config editor`. So I suspect that either the wiki has incorrect advice, or this bug has been fixed, and has since reappeared.

* [1] https://help.ubuntu.com/community/Sudoers?action=recall&rev=25#content