Message 75266 - Python tracker
Here's the output of configure. Just as Mark said, it looks this is due to a libm bug. """ $ grep tanh config.log configure:22062: checking whether tanh preserves the sign of zero | and tanh(-0.) == -0. */ | atan2(tanh(-0.), -1.) == atan2(-0., -1.)) exit(0); configure:22261: checking for atanh ac_cv_func_atanh=yes ac_cv_tanh_preserves_zero_sign=no """