RC3 is out with a few deps changes now that Ecto 3.0.0 is out. To update existing RC apps, simply remove an explicit :ecto dep from your mix.exs, and update your :phoenix_ecto and :ecto_sql deps to the following:
...,
{:ecto_sql, “~> 3.0-rc”},
{:phoenix_ecto, “~> 4.0”},
Also be sure to grab the latest project generator:
$ mix archive.uninstall phx_new
$ mix archive.install hex phx_new 1.4.0-rc.3
