[Nix-dev] How to downgrade or patch freetype-2.7 ?

[Volth]

Oh, LD_LIBRARY_PATH advice is very helpful. Some minor issues left
(including one of how how to concatenate my LD_LIBRARY_PATH and
OpenGL's), but it solved the mass-rebuild problem. Now I could patch
the library or even use the good old 2.6.

Fontconfig does not help here. The problem is with all fonts with
manual hinting, also with all old windows fonts. Those fonts are from
pre-anti-aliasing ages.
Full hinting enabled + anti-aliasing disabled is the only suitable
mode for them.

On 4/19/17, Thomas Tuegel <ttuegel at mailbox.org> wrote:
> Volth <volth at volth.com> writes:
>
>> Freetype changed defaults in 2.7, the truetype interpreter became v40
>> instead of v35.
>> The new defaults are incomatible in a weird way with some old fonts
>> (notably PragmataPro).
>
>> But on NixOS this - flipping one bit in libfreetype.so - means either
>> to recompile all NixOS (too many packages depends on freetype, not
>> only GUI apps, also devtools) or to live with corrupt nixstore.
>>
>> Is there a more elegant solution?
>
> There is a more elegant work-around, and possibly an actual solution.
>
> First, the workaround: add a modified FreeType library to
> LD_LIBRARY_PATH. This environment variable should be passed through to
> every program on NixOS because that is how we handle the impurity of
> OpenGL drivers.
>
> Second, I can probably fix the way PragmataPro renders by applying
> selective Fontconfig rules. Could you please tell me, what settings are
> you using in `fonts.fontconfig'? If you have changed any
> Fontconfig settings like DPI or hinting through your desktop
> environment, please share that also. Unfortunately, it is not possible
> to simply change the interpreter from v40 to v35 through Fontconfig
> rules. However, changing the hinting level for that font only can
> essentially achieve the same thing.
>
> Regards,
> Tom
>
>