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"
```
No release in almost half a decade, no maintainer in Nixpkgs, and
the README describes it as obsolete and recommends alternatives:
<978bc1926c/README.rst (obsolescence-notice)>.
This was supposed to happen in #294504, but the commit was accidentally
left out when splitting off some libpq-related changes. Originated in
#179962, by Sandro.
Co-authored-by: Sandro Jäckel <sandro.jaeckel@gmail.com>
Co-authored-by: Wolfgang Walther <walther@technowledgy.de>
The xxxFlagsArray variants were never meant to be used in nix code, at
least they can't be used properly without __structuredAttrs turned on.
If no spaces are passed in the argument the xxxFlagsArray can be
replaced as-is with the non-Array variant. When whitespace needs to be
passed, the derivation is additionally changed to enable
__structuredAttrs.
