apport-collect requires python2

I'm booted into a 16.04 maas rescue environment.

$ apport-collect
You need to run 'sudo apt-get install python-apport' for apport-collect to work.

running the provided command will get me a python2 stack.
python3-apport is already installed.

python3 should be used.

I then tried a stock bionic container, and run the same. The message changes to suggest python3-apport.

root@b1:~# apport-collect
You need to run 'sudo apt-get install python3-apport' for apport-collect to work.

That seems better. However, python3-apport is already installed.
# sudo apt-get install python3-apport
Reading package lists... Done
Building dependency tree
Reading state information... Done
python3-apport is already the newest version (2.20.8-0ubuntu8).

ProblemType: Bug
DistroRelease: Ubuntu 16.04
Package: apport 2.20.1-0ubuntu2.15
ProcVersionSignature: User Name 4.13.0-32.35~16.04.1-generic 4.13.13
Uname: Linux 4.13.0-32-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.15
Architecture: amd64
Date: Tue Feb 13 15:38:43 2018
PackageArchitecture: all
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: apport
UpgradeStatus: No upgrade log present (probably fresh install)

Related bugs:
 * bug 1748621: apport-collect won't work (bionic)