@elextr Thanks for the comments. I realize the debug message points that out, as I said in the initial post. The question remains: what to do about it? The documentation gives me no hints on 'locale' setup. It seems that GTK expects a locale configuration in some other way. The shell/term environment doesn't help:
``` env |grep UTF LC_MONETARY=de_DE.UTF-8 LC_NUMERIC=de_DE.UTF-8 LC_ALL=de_DE.UTF-8 LC_MESSAGES=de_DE.UTF-8 LC_COLLATE=de_DE.UTF-8 LANG=de_DE.UTF-8 LC_CTYPE=de_DE.UTF-8 LC_TIME=de_DE.UTF-8 ```
No, I am not starting geany from a shell. Just as an app from the GUI. btw, geany itself appears in German - according to my system setup
However, starting it from the terminal, I see, amongst other errors, the same GTK-Warning:
``` /Applications/Geany.app/Contents/MacOS/geany textaufgabenweg.tex 2018-06-19 14:46:54.895 defaults[979:23009] The domain/default pair of (.GlobalPreferences, AppleCollationOrder) does not exist /Applications/Geany.app/Contents/MacOS/geany: line 108: test: argument expected
(process:965): Gtk-WARNING **: Locale not supported by C library. Using the fallback 'C' locale. 2018-06-19 14:46:55.006 geany-bin[965:22992] *** WARNING: Method userSpaceScaleFactor in class NSView is deprecated on 10.7 and later. It should not be used in new applications. Use convertRectToBacking: instead.
```
the starter is a bash script. That multiple places have a export LANG=.... I suspect one of those sets `LANG="de.UTF-8"` when it should be setting `LANG="de_DE.UTF-8"` There simply is no `de.UTF-8` locale on this Mac.