The real problem here is the cryptic compiler messages. It is hard to tell whether the code itself is not compatible, or there is some additional libraries or configuration missing.
It has to be a standard SQL database as it will interact with other non Elixir programs. If anything I can switch to Postgres. It isn’t that critical now as I am at the learning stage, but it will be good for Ecto 2.0 to work with sqlite. As from this thread - Why would I choose Elixir as a general purpose programming language? - #10 by vonH - I am trying to use Elixir as a general purpose programming language independently of the Erlang/BEAM ecosystem, and full blown Erlang database systems and SQL server databases are not always appropriate there.