diff --git a/llvm/include/llvm/Support/FileCollector.h b/llvm/include/llvm/Support/FileCollector.h
--- a/llvm/include/llvm/Support/FileCollector.h
+++ b/llvm/include/llvm/Support/FileCollector.h
@@ -23,6 +23,7 @@
 /// the VFS.
 class FileCollector {
 public:
+  /// \p Root directory gets created in copyFiles unless it already exists.
   FileCollector(std::string Root, std::string OverlayRoot);
 
   void addFile(const Twine &file);
diff --git a/llvm/lib/Support/FileCollector.cpp b/llvm/lib/Support/FileCollector.cpp
--- a/llvm/lib/Support/FileCollector.cpp
+++ b/llvm/lib/Support/FileCollector.cpp
@@ -34,7 +34,6 @@
 
 FileCollector::FileCollector(std::string Root, std::string OverlayRoot)
     : Root(std::move(Root)), OverlayRoot(std::move(OverlayRoot)) {
-  sys::fs::create_directories(this->Root, true);
 }
 
 bool FileCollector::getRealPath(StringRef SrcPath,
@@ -150,6 +149,11 @@
 }
 
 std::error_code FileCollector::copyFiles(bool StopOnError) {
+  auto Err = sys::fs::create_directories(Root, /*IgnoreExisting=*/true);
+  if (Err) {
+    return Err;
+  }
+
   std::lock_guard<std::mutex> lock(Mutex);
 
   for (auto &entry : VFSWriter.getMappings()) {