emacs22 is suggested, and seems to have been the suggested emacs since at least precise. And yet, emacs22 hasn't even been in ubuntu since precise.
see for example:
http://packages.ubuntu.com/en/xenial/pydb
There is really no good reason why this couldn't be updated to emacs24
ProblemType: Bug
DistroRelease: Ubuntu 15.10
Package: pydb 1.26-1
ProcVersionSignature: Ubuntu 4.2.0-25.30-generic 4.2.6
Uname: Linux 4.2.0-25-generic i686
ApportVersion: 2.19.1-0ubuntu5
Architecture: i386
Date: Mon Jan 25 17:01:29 2016
InstallationDate: Installed on 2016-01-19 (6 days ago)
InstallationMedia: Ubuntu 15.10 "Wily Werewolf" - Release i386 (20151021)
PackageArchitecture: all
ProcEnviron:
LANGUAGE=en_CA:en
TERM=xterm
PATH=(custom, no user)
LANG=en_CA.UTF-8
SHELL=/bin/bash
SourcePackage: pydb
UpgradeStatus: No upgrade log present (probably fresh install)
from the duplicate ticket