Index: lld/trunk/ELF/LTO.cpp
===================================================================
--- lld/trunk/ELF/LTO.cpp
+++ lld/trunk/ELF/LTO.cpp
@@ -218,8 +218,12 @@
     Keep.push_back(GV);
   }
 
-  Mover.move(Obj->takeModule(), Keep,
-             [](GlobalValue &, IRMover::ValueAdder) {});
+  if (Error E = Mover.move(Obj->takeModule(), Keep,
+                           [](GlobalValue &, IRMover::ValueAdder) {})) {
+    handleAllErrors(std::move(E), [&](const llvm::ErrorInfoBase &EIB) {
+      fatal("failed to link module " + F.getName() + ": " + EIB.message());
+    });
+  }
 }
 
 static void internalize(GlobalValue &GV) {
Index: lld/trunk/test/ELF/lto/Inputs/irmover-error.ll
===================================================================
--- lld/trunk/test/ELF/lto/Inputs/irmover-error.ll
+++ lld/trunk/test/ELF/lto/Inputs/irmover-error.ll
@@ -0,0 +1,6 @@
+target triple = "x86_64-unknown-linux-gnu"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+!0 = !{ i32 1, !"foo", i32 2 }
+
+!llvm.module.flags = !{ !0 }
Index: lld/trunk/test/ELF/lto/irmover-error.ll
===================================================================
--- lld/trunk/test/ELF/lto/irmover-error.ll
+++ lld/trunk/test/ELF/lto/irmover-error.ll
@@ -0,0 +1,12 @@
+; RUN: llvm-as -o %t1.bc %s
+; RUN: llvm-as -o %t2.bc %S/Inputs/irmover-error.ll
+; RUN: not ld.lld -m elf_x86_64 %t1.bc %t2.bc -o %t 2>&1 | FileCheck %s
+
+; CHECK: failed to link module {{.*}}2.bc: linking module flags 'foo': IDs have conflicting values
+
+target triple = "x86_64-unknown-linux-gnu"
+target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
+
+!0 = !{ i32 1, !"foo", i32 1 }
+
+!llvm.module.flags = !{ !0 }