Abvm/blwm faulty when ra-deva is included

Glyphs
1

I have run into an extremely weird bug. I have two masters, compatible outlines etc., anchors set. When exporting the corresponding instances, mark attachment (specifically, abvm and blwm) doesn’t work in the export corresponding to the second master. I tried looking at the decompiled font binaries in Glyphs and found an extra lookup defined in the dist feature. The dist feature was also not present in the file that works.

I’ve sent the files to support@.

2

Exporting from Glyphs Mini works :sweat_smile:

3

The dist feature references the “deva” script tag, that is missing in the Languagesystems. So if you add

languagesystem dev2 dflt;
languagesystem deva dflt;

to it, works.

4

Makes sense, thanks. Should this not be added by Glyphs by default?

And why does removing the ra-deva make it work?

5

your languageSystem was not automatic. If you automate it, Glyphs will add it.

6

Thanks a lot for the pointer! That makes sense.