When unicode-math is used, the replacement of e.g. greek characters with its variants does not work as before:
\let\phi\varphi
What is the way to achieve the same with unicode-math?
minimal example:
\documentclass[a4paper]{article}
\usepackage{fontspec}
\usepackage{unicode-math}
%\setmathfont{MnSymbol}
%\setmathfont[range=\mathit/{num,latin,Latin,greek,Greek}]{MinionPro-It}
\let\phi\varphi
\let\epsilon\varepsilon
\begin{document}
\noindent
varphi: $\varphi$ works!\\
phi: $\phi$ should look the same, but does not!\\
I actually want to fix the missing epsilon in MinionPro:\\
varepsilon: $\varepsilon$ works!\\
epsilon: $\epsilon$ doesn't!\\
\end{document}