RTLD flags For Python3

[mdavis36]

scipy internally builds it's own qhull as a shared library that is imported at runtime for a couple of packages. When we build Spheral with clang, I find that if Spheral is imported before one of the select scipy packages it will fail with a runtime error. The solution seems to be to import a scipy package before importing the compiled Spheral package so that the LD runtime gets the scipy qhull library first.

qhull has an internal check to ensure any call to it's API is coming from the same type of library (i.e. shared vs static) and the shared library seems to take precedence over the static one for this test. I don't know why we haven't seen this before on clang but I'm confident it has to do with the ctype LD runtime flags we have to throw in Spheral.py when not using a gnu type compiler.

Python3 has better support for RTLD flags that Python2.7, after the Python3 port we should investigate this further.

[jmikeowen]

A simple workaround might be to import scipy in our Spheral.py front-end script before we import the compiled packages, if the RTLD flags are difficult to sort out.

[mdavis36]

That is exactly what we are doing to get around this now, I think it came in the Python3 PR

[jmikeowen]

Awesome, so should we close this issue? Or keep it open if we want to investigate the RTLD flags?

[mdavis36]

Keep it open for investigation of the RTLD flags, resolving the scipy problem might be a good way to investigate the proper solution to this