A new internal option `hardware.opengl.setLdLibraryPath` is added which controls if `LD_LIBRARY_PATH` should be set to `/run/opengl-driver(-32)/lib`. It is false by default and is meant to be set to true by any driver which requires it. If this option is false, then `opengl.nix` and `xserver.nix` will not set `LD_LIBRARY_PATH`.
Currently Mesa and NVidia drivers don't set `setLdLibraryPath` because they work with libglvnd and do not override libraries, while `amdgpu-pro`, `ati` and `parallels-guest` set it to true (the former two really need it, the last one doesn't build so is presumed to).
Additionally, the `libPath` attribute within entries of `services.xserver.drivers` is removed. This made `xserver.nix` add the driver path directly to the `LD_LIBRARY_PATH` for the display manager (including X server). Not only is it redundant when the driver is added to `hardware.opengl.package` (assuming that `hardware.opengl.enable` is true), in fact all current drivers except `ati` set it incorrectly to the package path instead of package/lib.
This removal of `LD_LIBRARY_PATH` could break certain packages using CUDA, but only those that themselves load `libcuda` or other NVidia driver libraries using `dlopen` (not if they just use `cudatoolkit`). A few have already been fixed but it is practically impossible to test all because most packages using CUDA are libraries/frameworks without a simple way to test.
Fixes#11434 if only Mesa or NVidia graphics drivers are used.
Back in 2013, update-mime-database started using fdatasync() to write out
its changes after processing each file in /share/mime, with the reasoning
that a corrupted database from an interruption midway would be
problematic for applications[1]. Unfortunately, this caused a
significant regression in the time required to run update-mime-database:
commonly from under a second to half a minute or more.
This delay affects the time required to build system-path on NixOS, when
xdg.mime.enable is true (the default). For example, on one of my systems
system-path builds in ~48 seconds, 45 of which are update-mime-database.
This makes rapidly building new system configurations not fun.
This commit disables the calls to fdatasync(). update-mime-database
checks an environment variable, PKGSYSTEM_ENABLE_FSYNC, to determine
whether it should sync, and we can set this to false. system-path
already only has whatever filesystem commit guarantees that the Nix
builder provides. Furthermore, there is no risk of a failed MIME
database update messing up existing packages, because this is Nix.
(This issue was also reported at and discussed by Debian, Red Hat, and
Gentoo at least.)
[1] https://bugs.freedesktop.org/show_bug.cgi?id=70366
This is actually very useful. Allows you to test switch-to-configuration
nesting.children is still currently still broken as it will throw
away 'too much' of the config, including the modules that make
nixos tests work in the first place. But that's something for
another time.
Upstream provides a much more featureful desktop entry file. If we use
that we take advantage of all of those features and don't have to maintain it
ourselves.
Aaron Andersen