numpy undefined symbol: PyFPE_jbuf

I had the same problem, probably you have installed numpy without Anaconda, so there is a conflict because of this, which numpy to use: that one installed with pip or with conda. When I removed non-Anaconda numpy, error gone.

pip uninstall numpy

For cython users:

This post was helpful. The post explains, that there is some flag (--with-fpectl), which is either set during the compilation of cpython or not. When a library has been compiled using a cpython without that flag, it is incompatible to a version with that flag being set. This effect does only show up when you use cython, as numpy itself does not use this extension.

As further stated in that post, my Ubuntu 16.04 has been created with this flag and Conda without it. For me, it was specifically the module hmmlearn throwing the undefined symbol error. This must be the case because it was shipped by Ubuntu with the flag being set and not by anaconda. So I uninstalled hmmlearn and manually installed it anew from sourcescode (Anaconda, unfortunately, does not offer hmmlearn). --> Works!