diff --git a/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp b/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
--- a/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
+++ b/llvm/lib/DebugInfo/DWARF/DWARFDebugFrame.cpp
@@ -1101,8 +1101,8 @@
           default:
             return createStringError(
                 errc::invalid_argument,
-                "unknown augmentation character in entry at 0x%" PRIx64,
-                StartOffset);
+                "unknown augmentation character %c in entry at 0x%" PRIx64,
+                AugmentationString[i], StartOffset);
           case 'L':
             LSDAPointerEncoding = Data.getU8(&Offset);
             break;