Helvet triggers font warnings with recent LaTeX2e

[callegar]

Brief outline of the bug

Loading helvet triggers font warnings when reading texmf-dist/tex/latex/psnfss/t1phv.fd

LaTeX Warning: Font shape declaration has incorrect series value `mc'.
               It should not contain an `m'! Please correct it.
               Found on input line 20.

A similar warning is repeated multiple times for different lines in t1phv.fd.

Either recent versions of LaTeX2e were unwillingly made incompatible with helvet or helvet in the psnfss bundle (which is declared as a required piece of LaTeX) needs updating.

Minimal example showing the bug

\RequirePackage{latexbug}
\documentclass{article}
\usepackage{helvet}
\begin{document}
{\sffamily Test}
\end{document}

Log file (required) and possibly PDF file

testme.log

[u-fischer]

This is known, see #299. But it wasn't yet possible to contact the maintainer of helvet:. The warnings are harmless, so you can ignore them for now.

[callegar]

Thanks for pointing out, in my search I initially missed it. And good to see confirmed that the warnings are totally harmless.

[FrankMittelbach]

.fd files have now been updated on CTAN but it will take until TL2020 that they automatically make it to the user desktops