To demonstrate [-Yno-lub](http://eed3si9n.com/stricter-scala-with-ynolub), this shows the code changes that removes lubing (Not all subprojects are done).
After I made the changes, I switched the Scala back to normal 2.12.10.
The current injection of the new nio keys will overwrite any definitions
of those keys in a build source. This is undesirable. The fix is to
create a mapping of scoped keys to settings and for each inject setting
key, if there is a previous key, put that definition after the injected
definition so that it can override it.
It is still possible for progress threads to leak so shut them down if
there are no active tasks. The report0 method will start up a new thread
if a task is added.
In some circumstances, sbt would generate a number of task progress
threads that could run concurrently. The issue was that the TaskProgress
could be shared by multiple EvaluateTaskConfigs if a dynamic task was
used. This was problematic because when a dynamic task completed, it
might call afterAllCompleted which would stop the progress thread. There
also was a race condition because multiple threads calling initial could
theoretically have created a new progress thread which would cause a
resource leak.
To fix this, we modify the shared task progress so that the `stop()`
method is a no-op. This should prevent dynamic tasks from stopping the
progress thread. We also defer the creation of the task thread until
there is at least one active task. This prevents a thread from being
created in the shell.
The motivation for this change was that I found that sometimes there was
a leaked progress thread that would make the shell not really work for
me because the progress thread would overwrite the shell prompt. This
change fixes that behavior and I was able to validate with jstack that
there was consistently either one or zero task progress threads at a
time (zero in the shell, one when tasks were actually running).
When running sbt -Dtask.timings=true, the task timings get printed to
the console which can overwrite the shell prompt. When we use a logger,
the timing lines are correctly separated from the prompt lines.
I incorrectly included the DeleteLine in the progress line length and
this could cause certain progress lines to be incorrectly reported as
multi line when they actually fit on a single terminal line.