Comment 2 for bug 1660903

So, in my PR 31348 [1] to setup the host for multiple architectures, I'm using 'dpkg --print-architecture' followed by 'dpkg --print-foreign-architectures' to tell what's already installed, and if not tell you what's required to add it. The error message will replace the error being discussed here, if I also use 'dpkg-architecture -L' in the error as per Kyle's suggestion.
Although if preferred I can make it two separate PRs.

[1] https://github.com/snapcore/snapcraft/pull/1348