Index: libunwind/CMakeLists.txt
===================================================================
--- libunwind/CMakeLists.txt
+++ libunwind/CMakeLists.txt
@@ -191,6 +191,7 @@
 add_compile_flags_if_supported(-Wsign-conversion)
 add_compile_flags_if_supported(-Wstrict-aliasing=2)
 add_compile_flags_if_supported(-Wstrict-overflow=4)
+add_compile_flags_if_supported(-Wunused-but-set-variable)
 add_compile_flags_if_supported(-Wunused-parameter)
 add_compile_flags_if_supported(-Wunused-variable)
 add_compile_flags_if_supported(-Wwrite-strings)
Index: libunwind/src/Unwind-EHABI.cpp
===================================================================
--- libunwind/src/Unwind-EHABI.cpp
+++ libunwind/src/Unwind-EHABI.cpp
@@ -461,6 +461,7 @@
       return _URC_FATAL_PHASE1_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -479,6 +480,7 @@
           frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
+#endif
 
     // If there is a personality routine, ask it if it will want to stop at
     // this frame.
@@ -580,6 +582,7 @@
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -596,6 +599,7 @@
           functionName, sp, frameInfo.lsda,
           frameInfo.handler);
     }
+#endif
 
     // If there is a personality routine, tell it we are unwinding.
     if (frameInfo.handler != 0) {
@@ -687,6 +691,7 @@
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -702,6 +707,7 @@
           (void *)exception_object, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
+#endif
 
     // Call stop function at each frame.
     _Unwind_Action action =
Index: libunwind/src/Unwind-seh.cpp
===================================================================
--- libunwind/src/Unwind-seh.cpp
+++ libunwind/src/Unwind-seh.cpp
@@ -244,6 +244,7 @@
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -259,6 +260,7 @@
           (void *)exception_object, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
+#endif
 
     // Call stop function at each frame.
     _Unwind_Action action =
Index: libunwind/src/UnwindLevel1.c
===================================================================
--- libunwind/src/UnwindLevel1.c
+++ libunwind/src/UnwindLevel1.c
@@ -68,6 +68,7 @@
       return _URC_FATAL_PHASE1_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -85,6 +86,7 @@
           (void *)exception_object, pc, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
+#endif
 
     // If there is a personality routine, ask it if it will want to stop at
     // this frame.
@@ -167,6 +169,7 @@
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -183,6 +186,7 @@
                                  functionName, sp, frameInfo.lsda,
                                  frameInfo.handler);
     }
+#endif
 
     // If there is a personality routine, tell it we are unwinding.
     if (frameInfo.handler != 0) {
@@ -258,6 +262,7 @@
       return _URC_FATAL_PHASE2_ERROR;
     }
 
+#ifndef NDEBUG
     // When tracing, print state information.
     if (_LIBUNWIND_TRACING_UNWINDING) {
       char functionBuf[512];
@@ -273,6 +278,7 @@
           (void *)exception_object, frameInfo.start_ip, functionName,
           frameInfo.lsda, frameInfo.handler);
     }
+#endif
 
     // Call stop function at each frame.
     _Unwind_Action action =