Get more tests working; make Nix build work

flake.nix

@@ -6,8 +6,77 @@
 
   outputs = { self, nixpkgs, flake-utils }:
     flake-utils.lib.eachSystem [ "x86_64-linux" ] (system:
-      let pkgs = nixpkgs.legacyPackages.${system}; in
-      rec {
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        inherit (pkgs) stdenv lib;
+
+      in rec {
+        defaultPackage = self.packages."${system}".apply;
+        packages.apply = stdenv.mkDerivation {
+          pname = "apply";
+          version = "2021-07-16";
+
+          src = ./.;
+
+          nativeBuildInputs = with pkgs; [ makeWrapper ];
+
+          # Overridden in tests
+          doCheck = false;
+          checkInputs = with pkgs; [
+            shellcheck
+            gnumake
+
+            bash
+            dash
+            ksh
+
+            # busybox as an input will break things
+          ];
+
+          # Test with each shell
+          checkPhase = ''
+            cd "$src"
+            make test
+
+            (
+              export PATH="${lib.makeBinPath (with pkgs; [ busybox gnumake shellcheck ])}"
+              make test-ash
+            )
+          '';
+
+          # Don't patch shebangs on everything or it'll get the 'lib' and 'run'
+          # scripts, which we need to be able to copy elsewhere.
+          dontPatchShebangs = true;
+
+          installPhase = ''
+            mkdir -p $out/bin/
+            cp ./{apply,lib,push,run} $out/bin/
+            chmod +x $out/bin/*
+          '';
+
+          postFixup = ''
+            for f in $out/bin/{apply,push}; do
+              patchShebangs "$f"
+              wrapProgram "$f" \
+                --suffix PATH ":" "${lib.makeBinPath (with pkgs; [ coreutils parallel openssh ])}"
+            done
+          '';
+
+          meta = with lib; {
+            homepage = "https://github.com/andrew-d/apply";
+            description = "TODO";
+            maintainers = with maintainers; [ andrew-d ];
+            license = licenses.bsd3;
+            platforms = platforms.unix;
+          };
+        };
+
+        defaultApp = self.apps."${system}".apply;
+        apps.apply = {
+          type = "app";
+          program = "${self.defaultPackage."${system}"}/bin/apply";
+        };
+
         devShell = pkgs.mkShell {
           buildInputs = with pkgs; [
             # Shells
@@ -21,36 +90,8 @@
           ];
         };
 
-        checks = let
-          commonDeps = with pkgs; [ gnumake shellcheck ];
-
-        in {
-          bash = pkgs.runCommand "lint" {
-            src = ./.;
-            nativeBuildInputs = commonDeps ++ (with pkgs; [ bash ]);
-          } ''
-            export SHELL="${pkgs.bash}/bin/bash"
-            make -C "$src" test-bash
-            touch "$out"
-          '';
-
-          dash = pkgs.runCommand "lint" {
-            src = ./.;
-            nativeBuildInputs = commonDeps ++ (with pkgs; [ dash ]);
-          } ''
-            export SHELL="${pkgs.dash}/bin/dash"
-            make -C "$src" test-dash
-            touch "$out"
-          '';
-
-          busybox = pkgs.runCommand "lint" {
-            src = ./.;
-            nativeBuildInputs = commonDeps ++ (with pkgs; [ busybox ]);
-          } ''
-            export SHELL="${pkgs.busybox}/bin/ash"
-            make -C "$src" test-ash
-            touch "$out"
-          '';
+        checks = {
+          apply = self.defaultPackage.${system}.overrideAttrs (super: { doCheck = true; });
         };
       }
     );