WIP: flakes hacking

default.nix

@@ -9,9 +9,10 @@
 { system ? builtins.currentSystem
 , crossSystem ? null
 , config ? { allowUnfreePredicate = (import ./nix/lib/unfree.nix).unfreePredicate; }
+, useFlakes ? false
   # Overrides for niv
 , sourcesOverride ? { }
-, packages ? import ./nix { inherit system crossSystem config sourcesOverride checkMaterialization enableHaskellProfiling; }
+, packages ? import ./nix { inherit system crossSystem config useFlakes sourcesOverride checkMaterialization enableHaskellProfiling; }
   # An explicit git rev to use, passed when we are in Hydra
   # Whether to check that the pinned shas for haskell.nix are correct. We want this to be
   # false, generally, since it does more work, but we set it to true in the CI

flake.nix

@@ -0,0 +1,30 @@
+{
+  description = "Flake for Plutus";
+
+  inputs = {
+    flake-utils.url = "github:numtide/flake-utils?rev=b543720b25df6ffdfcf9227afafc5b8c1fabfae8";
+  };
+
+  outputs = { self, flake-utils, ... }:
+    (flake-utils.lib.eachSystem [ "x86_64-linux" ] (system:
+      let
+        topLevel = import ./. {
+          inherit system;
+          useFlakes = true;
+        };
+
+        inherit (topLevel) pkgs plutus ownOverlays;
+        inherit (plutus) haskell iohkNix;
+        inherit (plutus.lib) buildPursPackage buildNodeModules filterNpm gitignore-nix;
+      in
+      rec {
+        packages = rec {
+          marlowe-playground-client = topLevel.marlowe-playground.client;
+          marlowe-playground-server = topLevel.marlowe-playground.server;
+          plutus-playground-client = topLevel.plutus-playground.client;
+          plutus-playground-server = topLevel.plutus-playground.server;
+          marlowe-website = topLevel.marlowe-web;
+          web-ghc-server = plutus.haskell.project.hsPkgs.web-ghc.components.exes.web-ghc-server;
+        };
+      }));
+}

nix/default.nix

@@ -2,24 +2,29 @@
 , crossSystem ? null
 , config ? { }
 , overlays ? [ ]
+, useFlakes ? false
 , sourcesOverride ? { }
 , checkMaterialization ? false
 , enableHaskellProfiling ? false
 }:
 let
-  sources = import ./sources.nix { inherit pkgs; }
-    // sourcesOverride;
+  sources = import ./sources.nix { inherit system pkgs; } // sourcesOverride;
   iohkNix = import sources.iohk-nix { };
   haskellNix = import sources."haskell.nix" {
+    inherit system;
     sourcesOverride = {
       hackage = sources."hackage.nix";
       stackage = sources."stackage.nix";
     };
   };
 
+  # For haskell.nix a different overlay has to be used for
+  # normal evaluation or when evaluated in a flake build
+  haskellNixOverlays = if useFlakes then [ haskellNix.allOverlays.combined-eval-on-build ] else haskellNix.overlays;
+
   extraOverlays =
     # Haskell.nix (https://github.com/input-output-hk/haskell.nix)
-    haskellNix.overlays
+    haskellNixOverlays
     # haskell-nix.haskellLib.extra: some useful extra utility functions for haskell.nix
     ++ iohkNix.overlays.haskell-nix-extra
     # iohkNix: nix utilities and niv:

nix/sources.json

@@ -51,15 +51,15 @@
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "haskell.nix": {
-        "branch": "master",
+        "branch": "pass-system-to-niv",
         "description": "Alternative Haskell Infrastructure for Nixpkgs",
         "homepage": "https://input-output-hk.github.io/haskell.nix",
-        "owner": "input-output-hk",
+        "owner": "tweag",
         "repo": "haskell.nix",
-        "rev": "87084d65a476cc826a0e8c5d281d494254f5bc7a",
-        "sha256": "168vj5zswhxvvgp39ksr400gl2szih9sjbcdz2wsb7r7rnwp42xp",
+        "rev": "3bf36164e9cb2e5df47551777d8e5386f10984ad",
+        "sha256": "09irl3svvjjzkl1k1i32i1iidm0zbqawqgrs6bbbs1hqjr63s2cw",
         "type": "tarball",
-        "url": "https://github.com/input-output-hk/haskell.nix/archive/87084d65a476cc826a0e8c5d281d494254f5bc7a.tar.gz",
+        "url": "https://github.com/tweag/haskell.nix/archive/3bf36164e9cb2e5df47551777d8e5386f10984ad.tar.gz",
         "url_template": "https://github.com/<owner>/<repo>/archive/<rev>.tar.gz"
     },
     "iohk-nix": {