bug#68860: race condition with make recheck

Hi Peter,

    The problem seems to be that both $(TESTS) and check_LIBRARIES depend on 
    libfoo.a and trigger compilation of foo.cc. 

Thanks much for the report and analysis. What you wrote looks sensible
to me.

    My understanding of parallel make is a bit hazy,

Me too :(. If anyone else here has a chance to look into this, that
would be great.

    One idea would to change the rule for recheck to

It looks plausible. Another possibility that comes to mind is to make
the recheck target more parallel to all, i.e., with a recheck-am
target. I', not sure.

    Please find attached a trimmed down example of the problem.

Thanks again. Will ponder. --best, karl.