Index: llvm/trunk/test/MC/AsmParser/invalid-asm-variant.s
===================================================================
--- llvm/trunk/test/MC/AsmParser/invalid-asm-variant.s
+++ llvm/trunk/test/MC/AsmParser/invalid-asm-variant.s
@@ -0,0 +1,3 @@
+//RUN:	not llvm-mc --disassemble -triple=x86_64 --output-asm-variant=2 %s -o - 2>&1 | FileCheck %s
+
+//CHECK: error: unable to create instruction printer for target triple 'x86_64' with assembly variant 2.
Index: llvm/trunk/tools/llvm-mc/llvm-mc.cpp
===================================================================
--- llvm/trunk/tools/llvm-mc/llvm-mc.cpp
+++ llvm/trunk/tools/llvm-mc/llvm-mc.cpp
@@ -563,6 +563,14 @@
     IP = TheTarget->createMCInstPrinter(Triple(TripleName), OutputAsmVariant,
                                         *MAI, *MCII, *MRI);
 
+    if (!IP) {
+      errs()
+          << "error: unable to create instruction printer for target triple '"
+          << TheTriple.normalize() << "' with assembly variant "
+          << OutputAsmVariant << ".\n";
+      return 1;
+    }
+
     // Set the display preference for hex vs. decimal immediates.
     IP->setPrintImmHex(PrintImmHex);