Add nix stuff to compile fully statically (still not working...)

default.nix

@@ -0,0 +1,46 @@
+# Run using:
+#
+#     $(nix-build --no-link -A fullBuildScript)
+# also the following might be needed:
+# sysctl kernel.unprivileged_userns_clone=1
+{
+    stack2nix-output-path ? "custom-stack2nix-output.nix",
+}:
+let
+  cabalPackageName = "geval";
+  compiler = "ghc844"; # matching stack.yaml
+
+  # Pin nixpkgs version.
+  pkgs = import (fetchTarball https://github.com/nh2/nixpkgs/archive/a2d7e9b875e8ba7fd15b989cf2d80be4e183dc72.tar.gz) {};
+
+  # Pin static-haskell-nix version.
+  static-haskell-nix = fetchTarball https://github.com/nh2/static-haskell-nix/archive/1d37d9a83e570eceef9c7dad5c89557f8179a076.tar.gz;
+
+  stack2nix-script = import "${static-haskell-nix}/static-stack2nix-builder/stack2nix-script.nix" {
+    inherit pkgs;
+    stack-project-dir = toString ./.; # where stack.yaml is
+    hackageSnapshot = "2019-05-08T00:00:00Z"; # pins e.g. extra-deps without hashes or revisions
+  };
+
+  static-stack2nix-builder = import "${static-haskell-nix}/static-stack2nix-builder/default.nix" {
+    normalPkgs = pkgs;
+    inherit cabalPackageName compiler stack2nix-output-path;
+    # disableOptimization = true; # for compile speed
+  };
+
+  # Full invocation, including pinning `nix` version itself.
+  fullBuildScript = pkgs.writeScript "stack2nix-and-build-script.sh" ''
+    #!/usr/bin/env bash
+    set -eu -o pipefail
+    STACK2NIX_OUTPUT_PATH=$(${stack2nix-script})
+    ${pkgs.nix}/bin/nix-build --no-link -A static_package --argstr stack2nix-output-path "$STACK2NIX_OUTPUT_PATH" "$@"
+  '';
+
+in
+  {
+    static_package = static-stack2nix-builder.static_package;
+    inherit fullBuildScript;
+    # For debugging:
+    inherit stack2nix-script;
+    inherit static-stack2nix-builder;
+}