Is testcoverage reliable when using `mock`/`meck`?

While I was debugging a CI error (not relevant here) I saw a huge amount of lines like the following appearing in the logs:

WARNING: Deleting data for module 'Elixir.App.Jobs' imported from
["/ramdisk/builds/app/Elixir.App.Jobs.1502.coverdata",
 "/ramdisk/builds/app/Elixir.App.Jobs_meck_original.1502.coverdata"]

I already know that the mentioned modules are mocked. Though the project in question uses both, Mock and Mox, in a way that is not easy to discover.

The lines above are just exemplary and happens for a lot of modules.

As all of them contain the term “meck_original” I assume, that Mock is somehow the culprit.

So far the backstory… Lets ask the actual question now:

Does this warning mean, that coverage data for this project is not reliable?