test: update mlton

tests/bench/flake.lock

@@ -80,22 +80,6 @@
         "type": "github"
       }
     },
-    "mltonNixpkgs": {
-      "locked": {
-        "lastModified": 1659446231,
-        "narHash": "sha256-hekabNdTdgR/iLsgce5TGWmfIDZ86qjPhxDg/8TlzhE=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "eabc38219184cc3e04a974fe31857d8e0eac098d",
-        "type": "github"
-      },
-      "original": {
-        "owner": "NixOS",
-        "ref": "nixos-21.11",
-        "repo": "nixpkgs",
-        "type": "github"
-      }
-    },
     "nix": {
       "inputs": {
         "lowdown-src": "lowdown-src",
@@ -203,7 +187,6 @@
           "flake-utils"
         ],
         "lean": "lean",
-        "mltonNixpkgs": "mltonNixpkgs",
         "nixpkgs": "nixpkgs_3",
         "temci": "temci"
       }

tests/bench/flake.nix

@@ -4,7 +4,6 @@
   inputs.flake-utils.follows = "lean/flake-utils";
   inputs.temci.url = github:Kha/temci;
   inputs.nixpkgs.url = github:NixOS/nixpkgs/nixpkgs-unstable;
-  inputs.mltonNixpkgs.url = github:NixOS/nixpkgs/nixos-21.11;
 
   outputs = inputs: inputs.flake-utils.lib.eachDefaultSystem (system: { packages = rec {
     leanPkgs = inputs.lean.packages.${system};
@@ -27,7 +26,11 @@
     ocaml = ocamlPkgs.ocaml;
     # note that this will need to be compiled from source
     ocamlFlambda = ocaml.override { flambdaSupport = true; };
-    mlton = inputs.mltonNixpkgs.legacyPackages.${system}.mlton;
+    # https://github.com/MLton/mlton/issues/473
+    mlton = pkgs.mltonHEAD.override {
+      rev = "082087f7f82021a5a84eac0a593b98ba7b16f7fe";
+      sha256 = "sha256-AILSBF+Yu+wmeOikwk/binhvjNZD7ZTLnpxnRKijIV0=";
+    };
     mlkit = pkgs.mlkit;
     swift = pkgs.swift;
     temci = inputs.temci.packages.${system}.default.override { doCheck = false; };