Send non-quiet repository rule output to stderr

Resolves #8077

Closes #10611.

PiperOrigin-RevId: 295352817
diff --git a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java
index 68bc84a..e7b0ad6 100644
--- a/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java
+++ b/src/main/java/com/google/devtools/build/lib/bazel/repository/skylark/SkylarkExecutionResult.java
@@ -172,7 +172,7 @@
       // exception when reaching a specific size.
       delegator.addSink(recorder);
       if (!quiet) {
-        delegator.addSink(OutErr.create(System.out, System.err));
+        delegator.addSink(OutErr.create(System.err, System.err));
       }
       try {
         String[] argsArray = new String[args.size()];