Fix flake for darwin, approxWith factorial.

Author: dmjio

flake.nix

@@ -198,7 +198,7 @@
           ps.shellFor {
             packages = ps: if hasArrayfire then [ ps.arrayfire ] else [ ];
             withHoogle = true;
-            buildInputs = with pkgs; (if isLinux then [ ocl-icd ] else [ darwin.apple_sdk.frameworks.Security ]);
+            buildInputs = with pkgs; (if isLinux then [ ocl-icd ] else [ ]);
             nativeBuildInputs = with pkgs; with ps; [
               # Building and testing
               cabal-install

test/ArrayFire/ArithSpec.hs

@@ -273,7 +273,11 @@ spec =
       it "factorial 5 = 120" $
         evalf (ArrayFire.factorial (scalar @Double 5)) `shouldBeApprox` 120
       it "factorial 10 = 3628800" $
-        evalf (ArrayFire.factorial (scalar @Double 10)) `shouldBeApprox` 3628800
+        -- factorial is computed via the platform libm gamma function, which is
+        -- not bit-exact: on macOS it lands ~2.3e-9 off, exceeding the default
+        -- relative tolerance (~1.6e-9 at this magnitude). Loosen it here.
+        approxWith 1e-7 1e-7 (evalf (ArrayFire.factorial (scalar @Double 10))) 3628800
+          `shouldBe` True
 
     describe "floor" $ do
       it "floor of 1.7 is 1" $