skopeo: don't set policy and tmpdir during build

pkgs/development/tools/skopeo/default.nix

@@ -12,7 +12,8 @@
 , fuse-overlayfs
 }:
 
-let
+buildGoModule rec {
+  pname = "skopeo";
   version = "0.2.0";
 
   src = fetchFromGitHub {
@@ -22,34 +23,22 @@ let
     sha256 = "09zqzrw6f1s6kaknnj3hra3xz4nq6y86vmw5vk8p4f6g7cwakg1x";
   };
 
-  defaultPolicyFile = runCommand "skopeo-default-policy.json" {} "cp ${src}/default-policy.json $out";
-
-  vendorPath = "github.com/containers/skopeo/vendor/github.com/containers/image/v5";
-
-in
-buildGoModule {
-  pname = "skopeo";
-  inherit version;
-  inherit src;
-
   outputs = [ "out" "man" ];
 
   vendorSha256 = null;
 
-  excludedPackages = [ "integration" ];
-
   nativeBuildInputs = [ pkg-config go-md2man installShellFiles makeWrapper ];
 
   buildInputs = [ gpgme ]
   ++ stdenv.lib.optionals stdenv.isLinux [ lvm2 btrfs-progs ];
 
-  buildFlagsArray = ''
-    -ldflags=
-    -X ${vendorPath}/signature.systemDefaultPolicyPath=${defaultPolicyFile}
-    -X ${vendorPath}/internal/tmpdir.unixTempDirForBigFiles=/tmp
+  buildPhase = ''
+    patchShebangs .
+    make binary-local
   '';
 
-  postBuild = ''
+  installPhase = ''
+    make install-binary PREFIX=$out
     make install-docs MANINSTALLDIR="$man/share/man"
     installShellCompletion --bash completions/bash/skopeo
   '';