In preparation for the deprecation of `stdenv.isX`.
These shorthands are not conducive to cross-compilation because they
hide the platforms.
Darwin might get cross-compilation for which the continued usage of `stdenv.isDarwin` will get in the way
One example of why this is bad and especially affects compiler packages
https://www.github.com/NixOS/nixpkgs/pull/343059
There are too many files to go through manually but a treewide should
get users thinking when they see a `hostPlatform.isX` in a place where it
doesn't make sense.
```
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv.is" "stdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenv'.is" "stdenv'.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "clangStdenv.is" "clangStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "gccStdenv.is" "gccStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "stdenvNoCC.is" "stdenvNoCC.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "inherit (stdenv) is" "inherit (stdenv.hostPlatform) is"
fd --type f "\.nix" | xargs sd --fixed-strings "buildStdenv.is" "buildStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "effectiveStdenv.is" "effectiveStdenv.hostPlatform.is"
fd --type f "\.nix" | xargs sd --fixed-strings "originalStdenv.is" "originalStdenv.hostPlatform.is"
```
Since version 2.0.0, proc-macro-crate has assumed it can exec()
`env::var("CARGO")` in order to run `cargo locate-project`.
This commit adds a crate override to proc-macro-crate which simply writes the
path to buildPlatform.cargo into the proc-macro-crate sources.
This way we don't need to set `env.CARGO` for every build that depends on
proc-macro-crate -- if we do that, the $CARGO environment variable would be
visible to the entire build. This could potentially lead to incredibly
hard-to-troubleshoot heisenbugs if there is some other crate that expects
`env::var("CARGO")` to exist -- that other crate would mysteriously work only
in projects that use proc-macro-crate but not anywhere else!
The build.rs script shipped with evdev-sys attempts to detect cross
compilation and uses a completely different codepath which does a
`git fetch` inside the build script. This doesn't work in nixpkgs.
This PR adds a `touch libevdev/.git` to trick the `build.rs` into
thinking that it is not necessary to do a `git fetch`.
Thanks to @figsoda for finding this more-elegant solution to the
problem (my original solution needed to patch `build.rs`):
https://github.com/NixOS/nixpkgs/pull/224893#pullrequestreview-1373809617
Tested on:
- [x] `aarch64-linux` (cross from `x86_64-linux`)
Also begin to start work on cross compilation, though that will have to
be finished later.
The patches are based on the first version of
https://reviews.llvm.org/D99484. It's very annoying to do the
back-porting but the review has uncovered nothing super major so I'm
fine sticking with what I've got.
Beyond making the outputs work, I also strove to re-sync the packages,
as they have been drifting pointlessly apart for some time.
----
Other misc notes, highly incomplete
- lvm-config-native and llvm-config are put in `dev` because they are
tools just for build time.
- Clang no longer has an lld dep. That was introduced in
db29857eb3, but if clang needs help
finding lld when it is used we should just pass it flags / put in the
resource dir. Providing it at build time increases critical path
length for no good reason.
----
A note on `nativeCC`:
`stdenv` takes tools from the previous stage, so:
1. `pkgsBuildBuild`: `(?1, x, x)`
2. `pkgsBuildBuild.stdenv.cc`: `(?0, ?1, x)`
while:
1. `pkgsBuildBuild`: `(?1, x, x)`
2. `pkgsBuildBuild.targetPackages`: `(x, x, ?2)`
3. `pkgsBuildBuild.targetPackages.stdenv.cc`: `(?1, x, x)`
