It seems it's all tooltips and tips, i.e. the overlay boxes, maybe other things as well. Missing are Czech letters like "čžšě...", probably non UTF font is used for rendering.

I guess the same problem will be with other locales that have non ASCII characters.

Created attachment 2033834 [details]
Missing characters in the tip box.

Created attachment 2033835 [details]
Missing characters in the tip box.

The same problem hit with the measurement dialog and probably all other "overlay" dialogs/boxes are affected.

I confirm the issue on prusa-slicer-2.7.4-1.fc40.x86_64 with

$ LC_ALL=cs_CZ.utf8 prusa-slicer

Jaroslav, would you remember if with previous versions the same dialogs were fine? IOW, is this a regression?

This has been a problem for a very long time.

I can confirm this happens at least in prusa-slicer-2.5.2-2.fc39.x86_64

I don't know when they introduced it, I haven't used this slicer much. I guess in tips/tooltips this was very minor problem, but now when they are adding more useful overlay dialogs (like the measurement tool in 2.6) it's more annoying.

Created attachment 2034031 [details]
Quick and dirty downstream fix

It seems you are not bundling the google font "NotoSans-Regular.ttf" into "/usr/share/PrusaSlicer/fonts". Attached is quick and dirty downstream fix that uses system font. You will also need to add the following into spec:

Requires: google-noto-sans-fonts

And for the CJK font also:

Requires: google-noto-sans-cjk-fonts

For the CJK fonts the path is:
/usr/share/fonts/google-noto-sans-cjk-fonts/

I will alter the patch.

Created attachment 2034034 [details]
Quick and dirty downstream fix

Also add to spec:

Requires: google-noto-sans-fonts
Requires: google-noto-sans-cjk-fonts

Maybe you could use "Recommends:".

Maybe you could omit the explicit CJK fonts dep, it's additional cca. 81 MB with probably no use for non APAC users and APAC users would probably already have it.

Changing version to f39, because the patch is the same and it's also affected. But I will be OK with the rawhide only fix.

You could also create font symlinks from /usr/share/PrusaSlicer/fonts to system fonts.

This does "fix" the problem for me:

sudo ln -s /usr/share/fonts/google-noto /usr/share/PrusaSlicer/fonts
sudo dnf install google-noto-sans-fonts

We could package that symbolic link. The only problem is we might hit https://docs.fedoraproject.org/en-US/packaging-guidelines/Directory_Replacement/ in case the fonts will ever be bundled.

I belive we should link the actual files.

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Reopened, it's still problem on F43 and the fix is simple. Personally, I don't care about the CJK so just the font for the EU is OK for me :).

The question marks instead of the characters aren't good. It's not only the tooltips, it's everywhere in the UI (e.g. the measurement dialog). Instructions how to fix are in comment 9 and others.

Created attachment 2137240 [details]
Missing characters in the UI

Thanks for report. Same problem is with Polish characters.

And it is clearly packaging issues as the same Prusa Slicer running on MacOS does not have that problem.

Created attachment 2137776 [details]
Properly displayed Polish national characters after patching app.

Thanks folks!

Refreshed patch, rebuilt package and it works!

Will send PR to the package.

PR to prusa-slicer package: https://src.fedoraproject.org/rpms/prusa-slicer/pull-request/67