flake.nix: Use own nix-eval-jobs fork

Currently we depend on changes that are not yet in a released
version of nix-eval-jobs. This pin needs to go before the 0.3
release.

flake.lock

@@ -16,7 +16,57 @@
         "type": "github"
       }
     },
+    "flake-utils": {
+      "locked": {
+        "lastModified": 1637014545,
+        "narHash": "sha256-26IZAc5yzlD9FlDT54io1oqG/bBoyka+FJk5guaX4x4=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "bba5dcc8e0b20ab664967ad83d24d64cb64ec4f4",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nix-eval-jobs": {
+      "inputs": {
+        "flake-utils": "flake-utils",
+        "nixpkgs": "nixpkgs"
+      },
+      "locked": {
+        "lastModified": 1641681369,
+        "narHash": "sha256-FpWFVYm3N8qcjWd2+d3SjL5BKt4ScCr4fyc1indYwTY=",
+        "owner": "zhaofengli",
+        "repo": "nix-eval-jobs",
+        "rev": "5248c68833076062c7cd20eef1a70294776cf265",
+        "type": "github"
+      },
+      "original": {
+        "owner": "zhaofengli",
+        "ref": "colmena",
+        "repo": "nix-eval-jobs",
+        "type": "github"
+      }
+    },
     "nixpkgs": {
+      "locked": {
+        "lastModified": 1639573498,
+        "narHash": "sha256-YAoywqjyjOJYuEZpA8sln84jk99GG9hYbPEYXwGEGGM=",
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "rev": "aef12c8678fd5e927edba764bd04f3ba2930ae15",
+        "type": "github"
+      },
+      "original": {
+        "owner": "NixOS",
+        "repo": "nixpkgs",
+        "type": "github"
+      }
+    },
+    "nixpkgs_2": {
       "locked": {
         "lastModified": 1642492175,
         "narHash": "sha256-lo5hxiY8U4eREChAR7JD94zns92hQqmp3wg3qTFolPA=",
@@ -35,7 +85,8 @@
     "root": {
       "inputs": {
         "flake-compat": "flake-compat",
-        "nixpkgs": "nixpkgs",
+        "nix-eval-jobs": "nix-eval-jobs",
+        "nixpkgs": "nixpkgs_2",
         "utils": "utils"
       }
     },

flake.nix

@@ -5,16 +5,22 @@
     nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
     utils.url = "github:numtide/flake-utils";
 
+    # not yet upstreamed
+    nix-eval-jobs.url = "github:zhaofengli/nix-eval-jobs/colmena";
+
     flake-compat = {
       url = "github:edolstra/flake-compat";
       flake = false;
     };
   };
 
-  outputs = { self, nixpkgs, utils, ... }: let
+  outputs = { self, nixpkgs, utils, nix-eval-jobs, ... }: let
     supportedSystems = [ "x86_64-linux" "i686-linux" "aarch64-linux" "x86_64-darwin" "aarch64-darwin" ];
   in utils.lib.eachSystem supportedSystems (system: let
-    pkgs = import nixpkgs { inherit system; };
+    pkgs = import nixpkgs {
+      inherit system;
+      overlays = [ self._evalJobsOverlay ];
+    };
   in rec {
     # We still maintain the expression in a Nixpkgs-acceptable form
     defaultPackage = self.packages.${system}.colmena;
@@ -58,6 +64,14 @@
       '';
     };
   }) // {
+    # For use in integration tests
+    _evalJobsOverlay = 
+      (final: prev: {
+        nix-eval-jobs = (final.callPackage nix-eval-jobs.outPath {}).overrideAttrs (old: {
+          version = "0.0.3-colmena";
+        });
+      });
+
     overlay = final: prev: {
       colmena = final.callPackage ./package.nix { };
     };

integration-tests/nixpkgs.nix

@@ -2,6 +2,7 @@ let
   flake = (import ../flake-compat.nix).defaultNix;
 in import flake.inputs.nixpkgs.outPath {
   overlays = [
+    flake._evalJobsOverlay
     flake.overlay
   ];
 }