fix tar command

overlays/cfg-if-fix.nix

···
 final: prev: {
-  buildPackage = args:
+  vendorCargoDeps = args:
     let
-      pname = args.pname or "";
+      previousOverride = args.overrideVendorCargoPackage or (_pkg: drv: drv);
+      newOverride = pkg: drv:
+        let
+          drv' = if pkg.name == "cfg-if" then
+                   drv.overrideAttrs (old: {
+                     unpackPhase = ''
+                       tar -xzf $src --no-same-owner
+                     '';
+                     requiredSystemFeatures = [ "local-build" ];
+                   })
+                 else
+                   drv;
+        in
+        previousOverride pkg drv';
     in
-    prev.buildPackage (args // (
-      if pname == "cfg-if" && args.version == "1.0.0" then {
-        requiredSystemFeatures = [ "local-build" ];
-        unpackPhase = ''
-          tar -xzf $src --no-same-owner
-        '';
-      } else { }
-    ));
-}
+    prev.vendorCargoDeps (args // { overrideVendorCargoPackage = newOverride; });
+}

pkgs/microcosm/default.nix

···
     nativeBuildInputs = nativeInputs;
     buildInputs = buildInputs;
     env = commonEnv;
-    overrideVendorCargoPackage = pkg: drv:
-      if pkg.name == "cfg-if" then
-        drv.overrideAttrs (old: {
-          unpackPhase = ''
-            tar -xzf $src --no-same-owner
-          '';
-          requiredSystemFeatures = [ "local-build" ];
-        })
-      else
-        drv;
   };
 
   members = [