install sha256sum with the option --zero using Nix

.github/workflows/ci.yml

@@ -12,5 +12,12 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
+      - uses: cachix/install-nix-action@v12
+        with:
+          install_url: https://github.com/numtide/nix-flakes-installer/releases/download/nix-2.4pre20201221_9fab14a/install
+          extra_nix_config: |
+            experimental-features = nix-command flakes
+      - name: build dependencies
+        run: nix build path://$PWD/
       - name: Run tests
-        run: ./test.py
+        run: PATH="$PWD/result/bin:$PATH" ./test.py

flake.lock

@@ -0,0 +1,22 @@
+{
+  "nodes": {
+    "nixpkgs-git": {
+      "locked": {
+        "narHash": "sha256-wLDweKqbmufa2wonCKBf4Wfl8I0eS1CGS7WdR5tPHKo=",
+        "type": "tarball",
+        "url": "https://github.com/NixOS/nixpkgs/archive/60330b60655b3fa3a18624bdd7069855bb37af99.tar.gz"
+      },
+      "original": {
+        "type": "tarball",
+        "url": "https://github.com/NixOS/nixpkgs/archive/60330b60655b3fa3a18624bdd7069855bb37af99.tar.gz"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs-git": "nixpkgs-git"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -0,0 +1,20 @@
+{
+  description = "";
+  inputs = {
+    nixpkgs-git.url = https://github.com/NixOS/nixpkgs/archive/60330b60655b3fa3a18624bdd7069855bb37af99.tar.gz; # was: 62ef779f2a5050549772722665bedf52f01268d2
+  };
+  outputs = { nixpkgs-git, ... }@inputs : {
+   defaultPackage.x86_64-linux =
+     let system = "x86_64-linux"; in
+     let nixpkgs = import nixpkgs-git { config = { allowUnfree = true;}; system = system; }; in
+
+     let mypackages = with nixpkgs; [ coreutils ]; in
+
+     with import nixpkgs-git { system = "x86_64-linux"; };
+     symlinkJoin {
+       name = "mypackages";
+       paths = lib.lists.unique mypackages;
+       postBuild = ''echo "links created"'';
+     };
+  };
+}