diff --git a/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/interop/RInteropExecuteNode.java b/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/interop/RInteropExecuteNode.java
index c0ba64a4b7892861ef69a5b26f97c09dd64308bd..9d0e64de79fbe8863c0ac03ef4fc22036c522035 100644
--- a/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/interop/RInteropExecuteNode.java
+++ b/com.oracle.truffle.r.engine/src/com/oracle/truffle/r/engine/interop/RInteropExecuteNode.java
@@ -36,7 +36,6 @@ import com.oracle.truffle.api.interop.ForeignAccess;
 import com.oracle.truffle.api.nodes.Node;
 import com.oracle.truffle.api.nodes.RootNode;
 import com.oracle.truffle.r.engine.TruffleRLanguage;
-import com.oracle.truffle.r.nodes.function.CallMatcherNode;
 import com.oracle.truffle.r.nodes.function.RCallNode;
 import com.oracle.truffle.r.runtime.ArgumentsSignature;
 import com.oracle.truffle.r.runtime.RArguments;
@@ -51,7 +50,6 @@ class RInteropExecuteNode extends RootNode {
     private final FrameSlot slot = emptyFrameDescriptor.addFrameSlot(argsIdentifier, FrameSlotKind.Object);
 
     @Child private RCallNode call = RCallNode.createExplicitCall(argsIdentifier);
-    @Child private CallMatcherNode callMatcher = CallMatcherNode.create(false, true);
     @Child private Node findContext = TruffleRLanguage.INSTANCE.actuallyCreateFindContextNode();
 
     private final ArgumentsSignature suppliedSignature;
diff --git a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/TestBase.java b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/TestBase.java
index 7677301bd5c062a2c191fee6d495cfcfe0ebf487..e3adf8b651ec1b7aa60d3e51f21bc8700ca61110 100644
--- a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/TestBase.java
+++ b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/TestBase.java
@@ -327,6 +327,8 @@ public class TestBase {
     private static int ignoredInputCount;
     private static int failedInputCount;
 
+    protected static String explicitTestContext;
+
     /**
      * A way to limit which tests are actually run. TODO requires more JUnit support for filtering
      * in the wrapper.
@@ -427,6 +429,9 @@ public class TestBase {
     }
 
     private static String getTestContext() {
+        if (explicitTestContext != null) {
+            return explicitTestContext;
+        }
         // We want the stack trace as if the JUnit test failed
         RuntimeException ex = new RuntimeException();
         // The first method not in TestBase is the culprit
diff --git a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/TestRBase.java b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/TestRBase.java
index a089f96f36a1acab73b792cd839bdb55b485b280..055d9d1d320556cef983e049d613c941439bf215 100644
--- a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/TestRBase.java
+++ b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/TestRBase.java
@@ -74,6 +74,7 @@ public class TestRBase extends TestBase {
             return;
         }
         for (int i = 0; i < files.length; i++) {
+            explicitTestContext = testDirName + "/R/" + files[i].getName();
             try {
                 BufferedReader bf = new BufferedReader(new FileReader(files[i]));
                 TestTrait testTrait = null;
@@ -98,6 +99,8 @@ public class TestRBase extends TestBase {
                 }
             } catch (IOException x) {
                 Assert.fail("error reading: " + files[i].getPath() + ": " + x);
+            } finally {
+                explicitTestContext = null;
             }
         }
     }
diff --git a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_parentframe.java b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_parentframe.java
index f3b0a6ced721b28ffc050b792ae45ac3d762ed75..24c720e2780c87ab7bd3e69c89039aed5f00cbbd 100644
--- a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_parentframe.java
+++ b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/builtins/TestBuiltin_parentframe.java
@@ -52,5 +52,4 @@ public class TestBuiltin_parentframe extends TestBase {
         assertEval("{ f <- function(frame) frame; g <- function() f(parent.frame()); g() }");
         assertEval("{ f <- function(frame) frame; g <- function() f(parent.frame(3)); g() }");
     }
-
 }
diff --git a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/parser/TestParser.java b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/parser/TestParser.java
index 7923cea6261cb4117d4d3bbf1a3474a6c6798c82..ac2c877be13cb47e943d1d537efc81fead017770 100644
--- a/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/parser/TestParser.java
+++ b/com.oracle.truffle.r.test/src/com/oracle/truffle/r/test/parser/TestParser.java
@@ -76,7 +76,7 @@ public class TestParser extends TestBase {
     @Test
     public void testLexerError() {
         // FastR provides a more accurate error message
-        assertEval(Output.ContainsError, "%0");
+        assertEval(Output.ContainsAmbiguousError, "%0");
     }
 
     /**