Why does scalatest mix up the output?

Question

I run my scalatest from sbt, and the output gets mixed up - scalatest prints all the test run, and comments to them, and somewhere in the middle it prints the statistics:

Answer 1

It looks to me the reason for that is that SBT by default executes the tests in parallel, the same way maven-surefire-plugin does.

As it is explained in ScalaTest wiki, this can be solved by:

Disable Parallel Execution of Tests By default, sbt runs all tasks in parallel. Because each test is mapped to a task, tests are also run in parallel by default. To disable parallel execution of tests:

parallelExecution in Test := false