Could not compile dependency :relx

[jononomo]

I'd like to look at the example, but I'm getting this error when I try to run mix deps.get

** (Mix) Could not compile dependency :relx,
"/Users/jon/.asdf/installs/elixir/1.12.1-otp-24/.mix/rebar3 bare compile --paths
/Users/jon/dev/phoenix_swoosh_example/_build/dev/lib/*/ebin" command failed.
You can recompile this dependency with "mix deps.compile relx",
update it with "mix deps.update relx" or clean it with "mix deps.clean relx"

None of the proposed solutions (update, clean, etc) fix the problem.

Also, I guess it would be nice to see this whole example updated to Phoenix 1.6, which comes with Swoosh included.