Its hard figuring out what the problem with a threaded app could be.  

Say somebody is running mozila and it locks up because of some thread
issue, what are they to report.  Alot of what thread to is
non-deterministic and any thousands of conditions could have caused the
problems.  Certainly its not practical to thift through thousands of
likes of mozilla source code to try to figure out what may have caused
the problem.  How would the debug log help here ? First it would
generate thousands of lines and second it would be imposible to figure
out what application was doing to generate the particular trace.

Sometimes threaded application even very common one are written without
regard for all possible race conditions and they may work on linux but
they deadlock on netbsd.  Obvisouly its not inconsivable scenerio.  I
dont think we can always blame the pthread library if some app locks up.

I think the best solution is to create some test cases that are simple
but also screwtinize the system in all kinds of situations. This way
they can be run on various platforms and people will have something to
report like this case caused a crash.

And yes lwp,sa calls need manpages.