hammer: ensure-hammer-deps broken on ubuntu 21.04

Hammer from 2.0.0 gives me the following error on ubuntu 21.04 when trying to run ensure hammer deps:

$ ./hammer.py ensure-hammer-deps
[HAMMER]  2021-09-29 12:53:26,976 >>>>> Executing vagrant version in /home/thomson/devel/kea
Installed Version: 2.2.9

Vagrant was unable to check for the latest version of Vagrant.
Please check manually at https://www.vagrantup.com
Traceback (most recent call last):
  File "/home/thomson/devel/kea/./hammer.py", line 2935, in <module>
    main()
  File "/home/thomson/devel/kea/./hammer.py", line 2921, in main
    ensure_hammer_deps()
  File "/home/thomson/devel/kea/./hammer.py", line 2401, in ensure_hammer_deps
    ver = m.group(1)
AttributeError: 'NoneType' object has no attribute 'group'

This may have to do with what @wlodek mentioned about the old vs new vagrant problems.