If you're getting that in a test, my guess is that you're not passing a context argument with `conn` in it to your test function (e.g. `test "foo", %{conn: conn} do`.
There's a deprecated `conn/0` function that you'll accidentally call instead if you forget to do this.
`conn` is the old version, newer versions of Phoenix use `build_conn`. Just use that
I don't generate my own controllers when installing Coherence. I just use the ones that come "out of the box."