In the following MWE, the package newtxmath is ignored and the Libertine fonts not loaded. The order of package loading is also irrelevant. If the polyglossia line is commented out, it works fine. Is there a way to use the two packages together? I am using TeXLive 2014.
\documentclass{report}
\usepackage[libertine]{newtxmath}
\usepackage{polyglossia}
\begin{document}
\noindent These are numbers in the text-mode: 0, 1, 2, 3, 4, 5, 6, 7\\
These are numbers in math-mode: $0, 1, 2, 3, 4, 5, 6, 7$
\end{document}
I see from the log file that polyglossia is loading fontspec which in turn is causing the problem... and I see that @Herbert has a solution for using fontspec and newtxmath together here Caveats of newtxmath and fontspec together so one important question here is - if his solution could be expanded to polyglossia.
