1 files changed, 11 insertions, 9 deletions
diff --git a/src/main/java/com/google/devtools/build/lib/syntax/EvalExceptionWithStackTrace.java b/src/main/java/com/google/devtools/build/lib/syntax/EvalExceptionWithStackTrace.java
index 173f2f7ec9..c76de98bc7 100644
--- a/src/main/java/com/google/devtools/build/lib/syntax/EvalExceptionWithStackTrace.java
+++ b/src/main/java/com/google/devtools/build/lib/syntax/EvalExceptionWithStackTrace.java
@@ -110,18 +110,24 @@ public class EvalExceptionWithStackTrace extends EvalException {
     addStackFrame(funcallDescription, location, false);
   }
 
-  /**
-   * Adds a line for the given frame.
-   */
+  /** Adds a line for the given frame. */
   private void addStackFrame(String label, Location location, boolean canPrint) {
-    // We have to watch out for duplicate since ExpressionStatements add themselves twice:
-    // Statement#exec() calls Expression#eval(), both of which call this method.
+    // TODO(bazel-team): This check was originally created to weed out duplicates in case the same
+    // node is added twice, but it's not clear if that is still a possibility. In any case, it would
+    // be better to eliminate the check and not create unwanted duplicates in the first place.
+    //
+    // The check is problematic because it suppresses tracebacks in the REPL, where line numbers
+    // can be reset within a single session.
     if (mostRecentElement != null && isSameLocation(location, mostRecentElement.getLocation())) {
       return;
     }
     mostRecentElement = new StackFrame(label, location, mostRecentElement, canPrint);
   }
 
+  private void addStackFrame(String label, Location location)   {
+    addStackFrame(label, location, true);
+  }
+
   /**
    * Checks two locations for equality in paths and start offsets.
    *
@@ -136,10 +142,6 @@ public class EvalExceptionWithStackTrace extends EvalException {
     }
   }
 
-  private void addStackFrame(String label, Location location)   {
-    addStackFrame(label, location, true);
-  }
-
   /**
    * Returns the exception message without the stack trace.
    */