Hi Werner,
> Your patch > > 6a92b1fadde26477a9179cbea988b3e04bd2decc > [gzip] Add support for `gzip' encoded header (#9812). > > makes fonts like > > > https://github.com/source-foundry/Hack/blob/master/build/web/fonts/hack-bold-subset.woff > PS: I compiled FreeType with 'make devel; make'. > I just got some time look at this and I think I have figured out the problem. In a make devel build, the internal copy of zlib is being used which is very old and thus fails with my patch. There are 3 ways to solve this problem: 1. In devel/ftoption.h:226 enable the macro #define FT_CONFIG_OPTION_SYSTEM_ZLIB 2. Revert my patch altogether. But then gzip encoded glyphs from ot-svg fonts won't work. (Don't know the impact on WOFF2 fonts) 3. Update the internal version of zlib to the newest version. Moazin