Uncover lines of an align environment with beamer and xelatex

Question

I'd like to do a line-by-line uncover of the lines in an align* environment in beamer. The solution posted here works great when compiled with pdflatex.

However, I am using xelatex for custom fonts, and the linked solution apparently doesn't work with xelatex.

Example ( I realize the algebra is not correct in the following, but I don't feel like redoing the screen shots :) ):

main.tex

\documentclass{beamer}

\setbeamercovered{transparent}

\begin{document}

\begin{frame}
\begin{align*}
    \onslide<1->{a &= \frac{b}{c} \\}
    \onslide<2->{b &= c \times d \\}
    \onslide<3>{\therefore \quad a &= \frac{d}{c}}
\end{align*}
\end{frame}

\end{document}

Compiling with pdflatex main works as expected, but xelatex main produces this funkiness where only the left side of the alignment character & of each line are shown in transparent:

Slide 1:

Slide 2:

Slide 3:

How can I uncover line-by-line in align* with transparency using xelatex?

Answer 1

No idea what the problem with xelatex is, but as a workaround you could wrap the left and right sides separately in \onslide:

\documentclass{beamer}

\setbeamercovered{transparent}

\begin{document}

\begin{frame}
\begin{align*}
    \onslide<1->{a &= \frac{b}{c} \\}
    \onslide<2->{b} &\onslide<2->{= c \times d} \\
    \onslide<3->{\therefore \quad a} &\onslide<3->{= \frac{d}{c}}
\end{align*}
\end{frame}

\end{document}