This reverts commit fb6d63f3fd.
I really hope this finally fixes#99236: evaluation on Hydra.
This time I really did check basically the same commit on Hydra:
https://hydra.nixos.org/eval/1618011
Right now I don't have energy to find what exactly is wrong in the
commit, and it doesn't seem important in comparison to nixos-unstable
channel being stuck on a commit over one week old.
- Fix wrong order in which font indexes are created
mkfontdir requires the file fonts.scale to consider scalable fonts,
thus, mkfontscale should be run before
- Search more font formats, in particular, bit-mapped formats
The incompatibility does not seem to exist any more: programs linked against fc 2.12
on fc 2.14 system seem to at least display text, even while printing tons of errors
(as long as you generate fc cache manually), and same thing the other way around.
Hopefully it will not be an issue in the future.
Turns out lot of software (including Chromium) use bundled fontconfig
so we either need to wrap every one of those, or re-introduce the global unversioned config.
The latter is easier but weakens hermetic configs. But perhaps those are not really worth the effort.
Falling back to unversioned `/etc/fonts/conf.d` when versioned one does not exist
is problematic since it only occurs on non-NixOS systems and those are likely
to have a different version of fontconfig. When those versions use incompatible
elements in the config, apps using fontconfig will crash.
Instead, we are now falling back to the in-package `fonts.conf` file that loads
both the versioned global `conf.d` directory and the in-package `conf.d` since using
upstream settings on non-NixOS is preferable to not being able to use apps there.
In fact, we would not even need to link `fonts.conf`, as the in-package `fonts.conf`
will be always used unless someone creates the global one manually (the option is still
retained if one wants to write a custom NixOS module and to avoid unnecessary stat call on NixOS).
Additionally, since the `fonts.conf` will always load `conf.d` from the package, we no longer
need to install them to sytem `/etc` in the module. This needed some mucking with `50-user.conf`
which disables configs in user directories (a good thing IMO, NixOS module will turn it back on)
but otherwise, it is cleaner. The files are still prioritized by their name, regardless of their location.
See https://github.com/NixOS/nixpkgs/pull/73795#issuecomment-634370125 for more information.
A centralized list for these renames is not good because:
- It breaks disabledModules for modules that have a rename defined
- Adding/removing renames for a module means having to find them in the
central file
- Merge conflicts due to multiple people editing the central file
In fontconfig’s 60-generic.conf, order of preference is estabilished for emoji
font family. Because fontconfig parses the config files in lexicographic order,
appending each <prefer> from <alias> element to the family’s prefer list
(to be prepended before the family) [1], our font family defaults stored
in 52-nixos-default-fonts.conf will take precedence. That is, of course, unless
the default „weak“ binding [2] is used. Emoji family binds strongly [3],
so we need to set binding to “same” for our <alias>es to be considered before
the ones from 60-generic.conf.
By default, we will set the option to all emoji fonts supported by fontconfig,
so that emoji works for user if they have at least one emoji font installed.
If they have multiple emoji fonts installed, we will use the fontconfig’s
order of preference [4].
[1]: https://github.com/bohoomil/fontconfig-ultimate/issues/51#issuecomment-64678322
[2]: https://www.freedesktop.org/software/fontconfig/fontconfig-user.html#AEN25
[3]: cc8442dec8
[4]: c41c922018
It currently lacks an emoji font-family which means it has to be
disabled for them to function [0]. Additionally it's fallen out of
necessity to ship custom font rendering settings (as far as I'm aware
of).
[0]: https://github.com/NixOS/nixpkgs/pull/67215
