Disable the S3 content-encoding patch

Since we're not using multi-part uploads at the moment, we can drop
this patch.

release-common.nix

@@ -64,10 +64,12 @@ rec {
         apis = ["s3" "transfer"];
         customMemoryManagement = false;
       }).overrideDerivation (args: {
+        /*
         patches = args.patches or [] ++ [ (fetchpatch {
           url = https://github.com/edolstra/aws-sdk-cpp/commit/3e07e1f1aae41b4c8b340735ff9e8c735f0c063f.patch;
           sha256 = "1pij0v449p166f9l29x7ppzk8j7g9k9mp15ilh5qxp29c7fnvxy2";
         }) ];
+        */
       }));
 
   perlDeps =

shell.nix

@@ -1,6 +1,6 @@
 { useClang ? false }:
 
-with import (builtins.fetchGit { url = https://github.com/NixOS/nixpkgs-channels.git; ref = "nixos-18.03"; }) {};
+with import (builtins.fetchGit { url = https://github.com/NixOS/nixpkgs-channels.git; ref = "nixos-18.09"; }) {};
 
 with import ./release-common.nix { inherit pkgs; };
 

src/libstore/s3-binary-cache-store.cc

@@ -292,11 +292,14 @@ struct S3BinaryCacheStoreImpl : public S3BinaryCacheStore
 
         if (transferManager) {
 
+            if (contentEncoding != "")
+                throw Error("setting a content encoding is not supported with S3 multi-part uploads");
+
             std::shared_ptr<TransferHandle> transferHandle =
                 transferManager->UploadFile(
                     stream, bucketName, path, mimeType,
                     Aws::Map<Aws::String, Aws::String>(),
-                    nullptr, contentEncoding);
+                    nullptr /*, contentEncoding */);
 
             transferHandle->WaitUntilFinished();