This adds convenience writers for self-contained Nim programs.
Those are compiled into very small binaries.
Test with: `nix build .#pkgs.tests.writers.{bin,simple,wrapping}.nim`
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"
```
Was trying out the recommended example for `writePython3Bin` and it
failed with:
```
Traceback (most recent call last):
File "/nix/store/gcmhfm7mslpndjasfhvs66f1ca24vxim-test_py3/bin/test_py3", line 4, in <module>
y = yaml.load("""
TypeError: load() missing 1 required positional argument: 'Loader'
```
Looks like `yaml.load(input)` was deprecated in 5.1: https://msg.pyyaml.org/load
`nixos-24.05` uses `6.0.1` so we're in the clear.
Add a makeWrapperArgs argument to all script writers under pkgs.writers.
This can be used to set, prefix, or suffix the PATH or other environment variables which improves the ability to generate scripts with reproducible behavior.
Some of the writers (writeBash, writeDash, writeFish, writeNu) previously did not support passing an argument set, for example
```
writeBash "example" "echo hello"
```
In order to add the new capability to these writers as well, their call signature is now overloaded in order to allow the following:
(The old call style from the example above remains intact)
```
writeBash "example"
{ makeWrapperArgs = [ "--prefix" "PATH" ":" "${pkgs.hello}/bin" ]; }
''
hello
''
```
Done as well:
- add tests
- add more docs
- fix some misleading docs
- extend existing docs with more examples
Add a makeWrapperArgs argument to all script writers under pkgs.writers.
This can be used to set, prefix, or suffix the PATH or other environment variables which improves the ability to generate scripts with reproducible behavior.
Some of the writers (writeBash, writeDash, writeFish, writeNu) previously did not support passing an argument set, for example
```
writeBash "example" "echo hello"
```
In order to add the new capability to these writers as well, their call signature is now overloaded in order to allow the following:
(The old call style from the example above remains intact)
```
writeBash "example"
{ makeWrapperArgs = [ "--prefix" "PATH" ":" "${pkgs.hello}/bin" ]; }
''
hello
''
```
Done as well:
- add tests
- add more docs
- fix some misleading docs
- extend existing docs with more examples
When authoring #220966, I missed that the `//` would take effect solely
in the else branch, fixing hledger-check-fancyassertions, but not
tests.writers.bin.haskell.
