Fontmake - avoiding overflow
Posted: 15 Aug 2022
I am wondering if anyone has insights into how to avoid an overflow post kern on when you run fontmake. I am using fontmake in the googlefonts/googlefonts-project-template.
The funny thing is I have been able to build without this error even with pretty big glyph sets! So I am guessed maybe something changed with either fontmake or kern-on. I'm hoping the error record has a clue. I will also be asking the folks at Google Fonts what they recon.
The bug I gets it reported like this in the build record
WARNING:fontTools.ttLib.tables.otBase:hb.repack failed to serialize 'GPOS', attempting fonttools resolutions ; the error message was: RepackerError
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 1, 'SubTableIndex:', None, 'ItemName:', None, 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet', 'ItemIndex:', 746)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet', 'ItemIndex:', 746)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 1, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 1, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 2, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 2, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 3, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 3, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 4, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 4, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 5, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 5, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 11, 'ItemName:', '<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 11, 'ItemName:', '<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 6, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
The funny thing is I have been able to build without this error even with pretty big glyph sets! So I am guessed maybe something changed with either fontmake or kern-on. I'm hoping the error record has a clue. I will also be asking the folks at Google Fonts what they recon.
The bug I gets it reported like this in the build record
WARNING:fontTools.ttLib.tables.otBase:hb.repack failed to serialize 'GPOS', attempting fonttools resolutions ; the error message was: RepackerError
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 1, 'SubTableIndex:', None, 'ItemName:', None, 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet', 'ItemIndex:', 746)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet', 'ItemIndex:', 746)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 0, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 1, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 1, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 2, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 2, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 3, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 3, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 4, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 4, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 5, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 5, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 11, 'ItemName:', '<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 11, 'ItemName:', '<none>', 'ItemIndex:', None)
INFO:fontTools.ttLib.tables.otBase:Attempting to fix OTLOffsetOverflowError ('GPOS', 'LookupIndex:', 0, 'SubTableIndex:', 6, 'ItemName:', 'PairSet.<none>', 'ItemIndex:', None)