Basic Go provider

examples/go/flake.nix

@@ -0,0 +1,10 @@
+{
+  description = "A go example for Packsnap";
+
+  inputs.packsnap.url = "../..";
+  inputs.flake-utils.url = "github:numtide/flake-utils";
+
+  outputs = { self, nixpkgs, flake-utils, packsnap }: flake-utils.lib.eachDefaultSystem (system: {
+      packages.packsnap-go = packsnap.lib.${system}.build { name = "packsnap-go"; path = ./.; };
+  });
+}

examples/go/go.mod

@@ -0,0 +1,3 @@
+module packsnap.farthergate.com/example-go
+
+go 1.16

examples/go/main.go

@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("Hello Nix!")
+}

lib/providers/default.nix

@@ -5,6 +5,7 @@ let
     (import ./node.nix { inherit pkgs npmlock2nix; })
     # Deno MUST come after Node!
     (import ./deno.nix { inherit pkgs; })
+    (import ./go.nix { inherit pkgs; })
   ];
 in with builtins;
 {

lib/providers/go.nix

@@ -0,0 +1,29 @@
+{ pkgs }:
+let plan = import ../plan { inherit pkgs; };
+in {
+  detect = path:
+    (builtins.pathExists /./${path}/go.mod);
+
+  plan = path:
+    let derivation = pkgs.stdenv.mkDerivation {
+      name = "packsnap-build-" + (builtins.baseNameOf path);
+      src = path;
+
+      nativeBuildInputs = [pkgs.go];
+
+      configurePhase = ''
+      go mod download
+      '';
+
+      buildPhase = ''
+      # this line removes a bug where value of $HOME is set to a non-writable /homeless-shelter dir (see https://github.com/NixOS/nix/issues/670#issuecomment-1211700127)
+      export HOME=$(pwd)
+      go build -o packsnap-out
+      '';
+
+      installPhase = ''
+      mkdir -p $out && cp packsnap-out $out
+      '';
+    };
+    in plan.buildPlan [] [derivation] [] "${derivation}/packsnap-out";
+}