"Unknown slot number of character" with microtype and siunitx

Question

This MWE produces the following warnings:

\documentclass{article}
\usepackage{microtype}
\usepackage[detect-all]{siunitx}
\begin{document}
    \num{1e-3}
\end{document}

I receive 5 warnings similar to this one (if I change the order of the two packages, the number of warnings increases to 34):

Package microtype Warning: Unknown slot number of character
(microtype)                `\textminus '
(microtype)                in font encoding `TS1' in protrusion list
(microtype)                `textcomp'.

I suspect these have been introduced by recent update of something (probably not microtype nor siunitx themselves). Can I get rid of these warnings without silencing them?

Answer 1

Load the fontencodings you want to use explicitly before loading microtype. E.g. here the TS1 encoding, either with fontenc or with textcomp:

\documentclass{article}
\usepackage[TS1,T1]{fontenc}
\usepackage{microtype}
\usepackage[detect-all]{siunitx}

\begin{document}
 abv   \num{1e-3}
\end{document}