I think you brought up the math and cmath errors before, and I never 
managed to get to the bottom of the problem.  I'll have another go.

I don't think the (c)math test failures should be regarded as terribly 
serious, though;  the tests are quite ridiculously strict.

Could you please tell me what

cmath.exp(complex(710.0, 1.5))

actually returns, if it doesn't raise OverflowError?

(Don't know nuffin about posix and subprocess.)