If I try printf 'X\n' | dmenu -fn '-misc-fixed-*-*-*-*-*-*-*-*-*-*-*-*'
with Dmenu 5.0, it runs with a fallback font that is clearly not the XLFD Fixed font. No warning, nothing at all on standard error to hint at the fact that it is not using it. I believe that either the manual page should document that XLFD is not supported anymore or that the stderr should be used to warn users that the font was not recognized and a fallback was used instead.
