Glyphs 3.0.5 (3124). I use variable font setting with Rename Glyphs custom parameter. Exporting a variable font fails with error “These glyphs are not compatible: tbar.varAlt01”.
When the parameter is off, the file exports nicely. Using the same custom parameter for regular OTFs works as it should. It is just when they are used together that results an error.
To me it looks like Glyphs expects the tbar and tbar.alt to have compatible paths? I just want them to swap places, so that tbar becomes tbar.alt and vice versa.
@GeorgSeifert I updated Glyphs with latest version. It still wont export. The compatibility error is gone but now I get error about features: Substitute glyph count (175) incompatible with target glyph count (137).
The classes are fine. I suspect the Rename Glyphs parameter messes this up.
I sent the file in question to support 21st of April. I can send it again if necessary.
I found the problem and fixed it. You can circumvent the problem by renaming the “Uppercase” class (e.g. to “uppercase”).
And you should not substitute lower to uppercase in the case feature. It is only meant to substitute alternate shapes that fit better with uppercase (e.g. parenthesis that are centered on the cap-height).