Index: ELF/Driver.cpp
===================================================================
--- ELF/Driver.cpp
+++ ELF/Driver.cpp
@@ -23,6 +23,7 @@
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/TargetSelect.h"
 #include "llvm/Support/raw_ostream.h"
+#include <cstdlib>
 #include <utility>
 
 using namespace llvm;
@@ -253,10 +254,15 @@
     return;
   }
 
-  if (auto *Arg = Args.getLastArg(OPT_reproduce)) {
+  const char *ReproducePath = nullptr;
+  if (Args.hasArg(OPT_reproduce))
+    ReproducePath = Args.getLastArg(OPT_reproduce)->getValue();
+  else
+    ReproducePath = ::getenv("LLD_REPRODUCE");
+  if (ReproducePath) {
     // Note that --reproduce is a debug option so you can ignore it
     // if you are trying to understand the whole picture of the code.
-    Cpio.reset(CpioFile::create(Arg->getValue()));
+    Cpio.reset(CpioFile::create(ReproducePath));
     if (Cpio) {
       Cpio->append("response.txt", createResponseFile(Args));
       Cpio->append("version.txt", getVersionString());
Index: test/ELF/reproduce.s
===================================================================
--- test/ELF/reproduce.s
+++ test/ELF/reproduce.s
@@ -25,7 +25,7 @@
 # RUN: mkdir -p %t.dir/build2/a/b/c
 # RUN: llvm-mc -filetype=obj -triple=x86_64-unknown-linux %s -o %t.dir/build2/foo.o
 # RUN: cd %t.dir/build2/a/b/c
-# RUN: ld.lld ./../../../foo.o -o bar -shared --as-needed --reproduce repro
+# RUN: env LLD_REPRODUCE=repro ld.lld ./../../../foo.o -o bar -shared --as-needed
 # RUN: cpio -id < repro.cpio
 # RUN: diff %t.dir/build2/foo.o repro/%:t.dir/build2/foo.o