This is correct, --warnings-as-errors
should only be failing if the warnings is emitting when compiling the project, not its dependencies.
In this case, I suspect this is because of meta programming - the library is probably generating code which gets compiled when compiling the project.
Instead I prefer to first run
mix deps.compile
(without--warnings-as-errors
) and thenmix compile --warnings-as-errors
to get warning-errors only from my application code.
This should be the same as just running mix compile --warnings-as-errors
, for the reason mentioned above.