Mix test issue -- no tests run SOLVED

Every so often I would run mix test in an umbrella application with no result. My versions are elixir v1.9.2 compiled with Erlang/OTP 22 and installed via asdf on MacOSX Mojave.

Here is the behavior:

my_user$ mix test

No tests seem to be run, there is no output.

The problem happened when I had the following option in my mix.exs in the project function:
def project do

elixirc_options: [warnings_as_errors: true],


A moment before it was working, but throwing an error of an unavailable module or undefined function which hadn’t been created yet. Then subsequent mix test runs behaved as above. Fixing the problem(s) signaled by the original warning(s) or commenting out or changing the warnings_as_errors: option to false fixed the issue! I was posting this as question, but solved it as I gathered info, go figure :wink:

1 Like