LuaTeX and selnolig

[_johnny7_ger at web.de]

Okay, as usual, I should have taken some more time before sending the
mail. I have now understood the required package fontspec is used by LyX
on choosing the option "Use non-TeX fonts". In this case, however, I can
no longer use URW Garamond but "Garamond" which doesn't look as good and
also apparently doesn't use ligatures. So this is a bit too much of a
hassle just to suppress some unwanted ligatures.

> I have a German document that I have always compiled with (the
> default) pdflatex. Now I want to suppress bad ligatures with the
> package selnolig that only works with LuaTeX. So I add
> \usepackage[ngerman]{selnolig} to my preamble, click on view with
> LuaTeX and get an error "TeX capacity exceeded, sorry [input stack
> size=5000]." Description: " \nolig{Auff[aeiloruyäöü]}{Auf|f}"
> So the Umlaute äöü are somehow not correctly encoded.
> Without using the package, LuaTeX compiles fine; I am on TeX Live 2019
> if this is relevant.
> The package documentation says selnolig should be loaded after babel,
> this is not how LyX does it, right, as the preamble is loaded first?
> It also says the package works better with babel than with the LaTeX
> package ngerman but I suppose I use babel? And I have to use the
> package fontspec and I don't know what LyX uses under the hood.
> Does the encoding play a role as LuaTeX only knows UTF-8? Under
> Document Settings - Language, I have chosen Language default as
> encoding (what is actually what for German?).
> Any ideas are much appreciated, thank you!