"function ExCoveralls.start/2 is undefined"


I’ve been facing the following error with ExCoveralls on an umbrella project for a while now:

$ MIX_ENV=test mix coveralls.html --umbrella

** (UndefinedFunctionError) function ExCoveralls.start/2 is undefined (module ExCoveralls is not available)
    (excoveralls 0.18.0) ExCoveralls.start("/Users/thbar/git/transport/transport-site/_build/test/lib/shared/ebin", [export: false, output: "cover", tool: ExCoveralls])
    (mix 1.15.5) lib/mix/tasks/test.ex:534: Mix.Tasks.Test.do_run/3
    (mix 1.15.5) lib/mix/task.ex:447: anonymous fn/3 in Mix.Task.run_task/5
    (mix 1.15.5) lib/mix/project.ex:458: Mix.Project.in_project/4
    (elixir 1.15.5) lib/file.ex:1624: File.cd!/2
    (mix 1.15.5) lib/mix/task.ex:604: anonymous fn/4 in Mix.Task.run_in_children_projects/2
    (elixir 1.15.5) lib/enum.ex:2510: Enum."-reduce/3-lists^foldl/2-0-"/3
    (mix 1.15.5) lib/mix/task.ex:603: Mix.Task.run_in_children_projects/2

I haven’t been able to bisect the origin of the problem so far (but will dive more into this).

I am unsure when this started popping, as we do not run the tool routinely.

Did anyone face this?


– Thibaut

I figured things out, ExCoveralls was not added to the sub-umbrella-apps!