The Overlays branch
This is a major reorganization in how haskell.nix is used, and marks our 1.0 release.
The branch doesn't build due to numerous issues that we believe to be with the CI
and not this branch. We expect only very minor adjustments prior to calling this the
official 1.0 release.
* Move iohk-nix patches into haskell.nix
This moves the customizations we did in iohk-nix
into haskell.nix via overlays and config.
Add bootPkgs logic
this moves the nuking of bootPkgs where it belongs. This should eventually still be
removed and replaced by a proper solution, that doesn't require the nuking of
bootPkgs.
Allow us to bootstrap binary ghcs and a cabal-install
With this we can do the following:
```
$ nix repl compiler/old-ghc-nix
nix-repl> :b (let pkgs = import <nixpkgs> {}; in with import ./. {}; import ./compiler/bootstrap/cabal-install.nix { inherit (pkgs) fetchurl stdenv zlib; inherit hackage
; ghc = ghc844; src = pkgs.fetchurl { url = "https://github.com/haskell/cabal/archive/Cabal-v3.0.0.0-rc3.tar.gz"; sha256 = "1zl2mgg8307ykq3v8nmafc6zdhhj1cw7w8ffpap16dsm6
5lbnx33"; }; })
```
which wile it may look daunting, will allow us to bootstrap a
cabal-install with a ghc. From that point onwards, we should be able to
build any hackage package via haskell.nix.
Pass through cabal-install version
Better threading of arguments.
Add bootstrap overlay
Allow alex + happy to be built
This still has a wart: we need nix-tools, and for that we use the ghc865 from
nixpkgs. Ideally we'd build nix-tools against a specific ghc, but then
we'd need a build expression for that.
Make ghcjs work
Building something like this:
```
nix build '(with import ./. { nixpkgs = ../nixpkgs; nixpkgsArgs = { crossSystem = { config = "js-unknown-ghcjs"; }; }; }; (haskell-nix.hackage-package { name = "hello"; version = "1.0.0.2"; })).components.exes.hello'
```
will now work. Assuming `nixpkgs` has been appropriately patched to support the `js-unknown-ghcjs` triple.
Also: this will need an additional `Cabal` patch, to make `Cabal` understand what it needs to do with: `dist/build/hello/hello: copyFile: does not exist (No such file or directory)`
It needs to learn that `dist/build/hello/hello.jsexe` is what it wants to copy and that that is a directory. Luckily we do have some code in Cabal already that does this for `.exe` on windows.
Build `js-unknown-ghcjs` packages with haskell.nix
Using the following expression:
```
with import ./. { nixpkgs = ../nixpkgs; nixpkgsArgs = { crossSystem = { config = "js-unknown-ghcjs"; }; }; };
let Cabal = buildPackages.haskell-nix.hackage-package {
name = "Cabal"; version = "2.4.1.0";
modules = [
{ packages.Cabal.patches = [ ./Cabal-install-folder.diff ]; }
];
}; in
(haskell-nix.hackage-package {
name = "hello"; version = "1.0.0.2";
modules = [
({config, ... }:{ packages.hello.package.setup-depends = [ Cabal ]; })
];}).components.exes.hello
```
in a `test.nix` file. And running
```
nix build -f ./test.nix
```
on it, will produce
```
./result
├── bin
│ └── hello.jsexe
│ ├── all.js
│ ├── all.js.externs
│ ├── index.html
│ ├── lib.js
│ ├── manifest.webapp
│ ├── out.frefs.js
│ ├── out.frefs.json
│ ├── out.js
│ ├── out.stats
│ ├── rts.js
│ └── runmain.js
└── share
└── doc
└── x86_64-linux-ghc-8.6.5
└── hello-1.0.0.2
└── LICENSE
6 directories, 12 files
```
- Dev note about nixpkgs pin
- More information about selecting a GHC version for cabal projects
- A little bit more information about cross compiling, but this is still incomplete.
Michael Peyton Jones
John A. Lotoski
Hamish Mackenzie
Domen Kožar
Rodney Lorrimar
zx9w
Moritz Angermann