OS X image and "Error: Unknown command: bundle"

[BanzaiMan]

Sounds like this:

MacOS build fails because of homebrew "bundle" unknown command

How frequently do the macOS virtual machines receive updates? My understanding is that Homebrew Bundle, which the Homebrew addon uses, now depends on Homebrew 2.2.5, and the macOS virtual machines currently ship an older version. Until the virtual machines receive an update, or something else changes, the workaround is to update it via update: true, as above.