From f4c39ef3255da75dc116a9c8c7358dae4833dbfb Mon Sep 17 00:00:00 2001
From: Greg Burd <gburd@symas.com>
Date: Tue, 12 Sep 2023 11:31:06 -0400
Subject: [PATCH] bring in flake-utils

---
 TODO       | 10 ++++++--
 flake.lock | 69 +++++++++++++++++++++++++++++++++++++++++++++++-------
 flake.nix  | 20 +++++++++++-----
 hello.c    |  4 ++--
 4 files changed, 84 insertions(+), 19 deletions(-)

diff --git a/TODO b/TODO
index cf131dd..20f44b3 100644
--- a/TODO
+++ b/TODO
@@ -1,7 +1,13 @@
 * add second build target `world.c`
 * add GitHub workflow to build all targets, upload/publish all artifacts
+  * deb, rpm, tgz of source
+  * Docker container on DockerHub, GitHub Container Repository (ghcr.io)
+    * containers could have multiple tags as in `latest` and `1.0.0`
 * add Nix Flake
 * devshell
 * direnv/envrc
-* build windows
-
+* build windows MSYS2
+* formatting
+* lint
+* security audits
+* Gitpod
diff --git a/flake.lock b/flake.lock
index 4301e9d..9004631 100644
--- a/flake.lock
+++ b/flake.lock
@@ -1,24 +1,75 @@
 {
   "nodes": {
-    "nixpkgs": {
+    "flake-compat": {
+      "flake": false,
       "locked": {
-        "lastModified": 1659914493,
-        "narHash": "sha256-lkA5X3VNMKirvA+SUzvEhfA7XquWLci+CGi505YFAIs=",
-        "owner": "NixOS",
-        "repo": "nixpkgs",
-        "rev": "022caabb5f2265ad4006c1fa5b1ebe69fb0c3faf",
+        "lastModified": 1673956053,
+        "narHash": "sha256-4gtG9iQuiKITOjNQQeQIpoIB6b16fm+504Ch3sNKLd8=",
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "rev": "35bb57c0c8d8b62bbfd284272c928ceb64ddbde9",
         "type": "github"
       },
       "original": {
-        "id": "nixpkgs",
-        "ref": "nixos-21.05",
-        "type": "indirect"
+        "owner": "edolstra",
+        "repo": "flake-compat",
+        "type": "github"
+      }
+    },
+    "flake-utils": {
+      "inputs": {
+        "systems": "systems"
+      },
+      "locked": {
+        "lastModified": 1694529238,
+        "narHash": "sha256-zsNZZGTGnMOf9YpHKJqMSsa0dXbfmxeoJ7xHlrt+xmY=",
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "rev": "ff7b65b44d01cf9ba6a71320833626af21126384",
+        "type": "github"
+      },
+      "original": {
+        "owner": "numtide",
+        "repo": "flake-utils",
+        "type": "github"
+      }
+    },
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1694532420,
+        "narHash": "sha256-eOebmMxt5B8nmW5u8P6BkYR9tLwcyq74fnsBBZmBSNQ=",
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "rev": "80616a47486f85bbe60650b6770cf8129333a26f",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nixos",
+        "repo": "nixpkgs",
+        "type": "github"
       }
     },
     "root": {
       "inputs": {
+        "flake-compat": "flake-compat",
+        "flake-utils": "flake-utils",
         "nixpkgs": "nixpkgs"
       }
+    },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
     }
   },
   "root": "root",
diff --git a/flake.nix b/flake.nix
index 2d4bb34..a4bd46d 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,9 +2,16 @@
   description = "An over-engineered Hello World in C";
 
   # Nixpkgs / NixOS version to use.
-  inputs.nixpkgs.url = "nixpkgs/nixos-21.05";
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs";
+    flake-utils.url = "github:numtide/flake-utils";
+    flake-compat = {
+      url = "github:edolstra/flake-compat";
+      flake = false;
+    };
+  };
 
-  outputs = { self, nixpkgs }:
+  outputs = { self, nixpkgs, flake-utils, flake-compat }:
     let
 
       # to work with older version of flakes
@@ -36,6 +43,7 @@
           src = ./.;
 
           nativeBuildInputs = [ autoreconfHook ];
+          enableParallelBuilding = true;
         };
 
       };
@@ -46,12 +54,12 @@
           inherit (nixpkgsFor.${system}) hello;
         });
 
-      # The default package for 'nix build'. This makes sense if the
-      # flake provides only one package or there is a clear "main"
-      # package.
+      # The default package for 'nix build'. This makes sense if the flake
+      # provides only one package or there is a clear "main" package.
       defaultPackage = forAllSystems (system: self.packages.${system}.hello);
 
-      # A NixOS module, if applicable (e.g. if the package provides a system service).
+      # A NixOS module, if applicable (e.g. if the package provides a system
+      # service).
       nixosModules.hello =
         { pkgs, ... }:
         {
diff --git a/hello.c b/hello.c
index d67cd5d..cb63c86 100644
--- a/hello.c
+++ b/hello.c
@@ -1,6 +1,6 @@
 #include "stdio.h"
 
-int main(int argc, char * * argv)
+int main(int argc, char **argv)
 {
-    printf("Hello Nixers!\n");
+    printf("Hello, world!\n");
 }