This overlay helps accessing common executable components.
Typically we want to make these available in a nix-shell
created with shellFor. In most cases the package name
will be the same as the executable, but we have a
`toolPackageName` mapping to help when it is not.
```
# To get a single tool:
haskell-nix.tool "cabal" "3.2.0.0"
# This does the same thing as:
(haskell-nix.hackage-package {
name = "cabal-install"
version = "3.2.0.0"
}).components.exes.cabal
# To get an attr set containing multiple tools:
haskell-nix.tools { cabal = "3.2.0.0"; hlint = "2.2.11"; }
# To add tools to a shell:
shellFor { tools = { cabal = "3.2.0.0"; hlint = "2.2.11"; }; }
```
When used in shellFor the tools will be compiled with the same version
of ghc used in the shell (the build ghc in the case of cross
compilation).
Instead of a version string we can use an attr set containing
arguments that will be passed to `cabalProject`.
For instance to specify the ghc used to compile. Use:
```
haskell-nix.tool "cabal" {
version = "3.2.0.0";
ghc = haskell-nix.compiler.ghc883;
}
```
* Remove unused (and broken) test files
* Make default.nix expose pinned nixpkgs
Also make `nixpkgs/default.nix` just an attribute set of sources.
This is simpler, and consistent with what e.g. `niv` does.
* Add backwards compatibility shim, and version argument to allow evolution in future
* Fix some missed things
* Fix and improve quickstart
* Updated the haskell.nix imports to overlay style
Some of the examples in the documentation were still passing an empty
set to the haskell.nix imports but this is no longer valid because the
import now results in a set rather than a function.
* Fix overlay imports in docs
Import an overlayed nixpkgs rather than just the overlay.
Thanks to angerman for noticing this error.