Option no-math of package fontspec causes \degree to print nothing

[mrpiggi]

\degree prints nothing with v3 and no-math passed to fontspec (new issue from #351 (comment))

\documentclass{article}
\usepackage[no-math]{fontspec}
\usepackage{siunitx}
\begin{document}
ang: \ang{180}
degree: \SI{180}{\degree}?
Celsius: \SI{180}{\celsius}?
\end{document}

[josephwright]

This is happening as I've tried as far as possible to leave unit definitions with 'just the characters'. For the degree symbol, I know that doesn't work for classical LaTeX, so I swap out for \text{\textdegree}, which does work in all cases. However, I'd left the fontspec case alone as usually it can print a math mode degree symbol. I'll go with the easiest fix: just use the same setup for fontspec as without it (there's currently no public test for the no-math option, and it doesn't really seem worth asking for one here as it's something that can be fixed another way).

[josephwright]

Is a fix urgent, BTW? You should be fine with

\DeclareSIUnit[quantity-product = ]\degree{\text{\textdegree}}
\DeclareSIUnit\degreeCelsius{\text{\textdegree}C}

until I do the next release.

[mrpiggi]

Since a workaround exists, there is no urgency.

[josephwright]

@mrpiggi OK, I'll wait a few days to see if there is anything else at the moment