fetchgx: support hash attribute

pkgs/build-support/fetchgx/default.nix

@@ -1,30 +1,31 @@
-{ stdenvNoCC, gx, gx-go, go, cacert }:
+{ lib, stdenvNoCC, gx, gx-go, go, cacert }:
 
-{ name, src, sha256 }:
+lib.fetchers.withNormalizedHash { } (
+  { name, src, outputHash, outputHashAlgo }:
 
-stdenvNoCC.mkDerivation {
+  stdenvNoCC.mkDerivation {
-  name = "${name}-gxdeps";
+    name = "${name}-gxdeps";
-  inherit src;
+    inherit src;
 
-  nativeBuildInputs = [ cacert go gx gx-go ];
+    nativeBuildInputs = [ cacert go gx gx-go ];
 
-  outputHashAlgo = "sha256";
+    inherit outputHash outputHashAlgo;
-  outputHashMode = "recursive";
+    outputHashMode = "recursive";
-  outputHash = sha256;
 
-  dontConfigure = true;
+    dontConfigure = true;
-  doCheck = false;
+    doCheck = false;
-  doInstallCheck = false;
+    doInstallCheck = false;
 
-  buildPhase = ''
+    buildPhase = ''
-    export GOPATH=$(pwd)/vendor
+      export GOPATH=$(pwd)/vendor
-    mkdir -p vendor
+      mkdir -p vendor
-    gx install
+      gx install
-  '';
+    '';
 
-  installPhase = ''
+    installPhase = ''
-    mv vendor $out
+      mv vendor $out
-  '';
+    '';
 
-  preferLocalBuild = true;
+    preferLocalBuild = true;
-}
+  }
+)