calamari virtualenv aplies SWIG flag cerrosaswarn too broadly
we added https://github.com/joehandzik/calamari/commit/23523483ca74f5f1474e0eac836e6eb58d8b9c38
to allow m2crypto to be built in centos7
other requirements in requirements.txt will get the same treatment and could fail silently.
The options come to mind for fixing this (in order of preference):
1. treat m2crypto as a system level package dependency
2. fix whatever is broken in m2crypto upstream
3. narrow the salt to build just m2crypto with this flag