remove unnecessary directory level

default.nix

@@ -0,0 +1,29 @@
+{ pkgs ? import (
+  builtins.fetchGit {
+    name = "nixpkgs-pinned";
+    url = https://github.com/NixOS/nixpkgs/;
+    ref = "refs/heads/release-20.03";
+    rev = "da7ddd822e32aeebea00e97ab5aeca9758250a40";
+  }) {},
+  compiler ? "ghc865"
+}:
+
+let
+  hp = pkgs.haskell.packages."${compiler}";
+  src = pkgs.nix-gitignore.gitignoreSource [] ./.;
+  drv = hp.callCabal2nix "Hash2Pub" "${src}/Hash2Pub.cabal" {};
+in
+{
+  my_project = drv;
+  shell = hp.shellFor {
+    withHoogle = true;
+    packages = p: [ drv ];
+    buildInputs = with hp;
+      [
+        haddock
+        cabal-install
+        hlint
+        pkgs.python3Packages.asn1ate
+      ];
+  };
+}