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.
This reverts commit edf2541f02.
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. Given that programs
linked against fc 2.12.6 on fc 2.13.92 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.
We give up on the hermetic configs in exchange for getting rid of lot of complexity.
With previous patch, we no longer load non-versioned fonts.conf file to avoid incompatibilities
but this also means fontconfig will not load system-wide installed fonts on non-NixOS systems.
As a compromise, let's hardcode the FHS font paths to the built-in config so that the system
fonts work there. Unlike with the system config we do not need to worry about compatibility as
incompatible font files will be simply ignored.
Of course there will still be disparity if the system install fonts to some other location than
these two but I am afraid this is the best we can do.
See https://github.com/NixOS/nixpkgs/pull/73795#issuecomment-635771967 for discussion.
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.
Since fontconfig-2.11 the xml:space attribute makes it reject
/etc/fonts/fonts.conf, so it renders garbage and eats lots of CPU.
To use anything linked to fontconfig-2.11 you need to have this patch
applied to your running NixOS. That's why I'm pushing it to master
before the fontconfig update (as soon as I found and tested the fix).
Otherwise the user won't be able to override anything specified in
NixOS' /etc/fonts/conf.d, since ~/.config/fontconfig is included from
upstream fonts/conf.5/50-user.conf.
support.
* New function makeFontsConf to generate a fontconfig configuration
file. Moved from NixOS.
* dot2pdf: use makeFontsConf to generate a fonts.conf containing just
the Ghostscript fonts (see NIXPKGS-29).
* dot2pdf: generate PDF directly, don't go through PS. Note that this
and using fontconfig changes the interpretation of "fontname"
attributes in dot graphs.
svn path=/nixpkgs/trunk/; revision=12251
