MRI backtrace should not include native lines

headius · headius · commit b0e4c91edee6 · 2026-01-06T01:03:00.000-06:00
At some point, we started including native .java lines in the MRI- formatted trace. This was probably unintended, since MRI-format traces should always follow CRuby's standard of replacing native call frames with the most recent Ruby frame. See #9154 for some discussion of filtering and omitting internal frames (that PR is about Ruby, but the same filtering already applied to native frames used in `caller`). This patch uses the same backtrace gathering logic for the MRI format as it does for `caller`, since in both cases users expect not to see .java frames for internal methods, and now with Ruby 4.0 they will also expect not to see internal Ruby sources.
diff --git a/core/src/main/java/org/jruby/runtime/backtrace/TraceType.java b/core/src/main/java/org/jruby/runtime/backtrace/TraceType.java
@@ -174,7 +174,7 @@ public static TraceType traceTypeFor(String style) {
         else if (style.equalsIgnoreCase("ruby_framed")) return new TraceType(Gather.NORMAL, Format.JRUBY);
         else if (style.equalsIgnoreCase("normal")) return new TraceType(Gather.NORMAL, Format.JRUBY);
         else if (style.equalsIgnoreCase("full")) return new TraceType(Gather.FULL, Format.JRUBY);
-        else if (style.equalsIgnoreCase("mri")) return new TraceType(Gather.NORMAL, Format.MRI);
+        else if (style.equalsIgnoreCase("mri")) return new TraceType(Gather.CALLER, Format.MRI);
         else return new TraceType(Gather.NORMAL, Format.JRUBY);
     }
 
@@ -228,7 +228,7 @@ public BacktraceData getBacktraceData(ThreadContext context, Stream<StackWalker.
         },
 
         /**
-         * Normal Ruby-style backtrace, showing only Ruby and core class methods.
+         * Normal JRuby-style backtrace, showing internal and external Ruby lines and bound core class methods.
          */
         NORMAL {
             public BacktraceData getBacktraceData(ThreadContext context, Stream<StackWalker.StackFrame> stackStream) {
