Index: cfe/trunk/include/clang/DirectoryWatcher/DirectoryWatcher.h
===================================================================
--- cfe/trunk/include/clang/DirectoryWatcher/DirectoryWatcher.h
+++ cfe/trunk/include/clang/DirectoryWatcher/DirectoryWatcher.h
@@ -99,10 +99,10 @@
         : Kind(Kind), Filename(Filename) {}
   };
 
-  /// Asserts if \param Path doesn't exist or isn't a directory.
+  /// llvm fatal_error if \param Path doesn't exist or isn't a directory.
   /// Returns llvm::Expected Error if OS kernel API told us we can't start
   /// watching. In such case it's unclear whether just retrying has any chance
-  /// to succeeed.
+  /// to succeed.
   static llvm::Expected<std::unique_ptr<DirectoryWatcher>>
   create(llvm::StringRef Path,
          std::function<void(llvm::ArrayRef<DirectoryWatcher::Event> Events,
Index: cfe/trunk/lib/DirectoryWatcher/linux/DirectoryWatcher-linux.cpp
===================================================================
--- cfe/trunk/lib/DirectoryWatcher/linux/DirectoryWatcher-linux.cpp
+++ cfe/trunk/lib/DirectoryWatcher/linux/DirectoryWatcher-linux.cpp
@@ -325,7 +325,9 @@
     StringRef Path,
     std::function<void(llvm::ArrayRef<DirectoryWatcher::Event>, bool)> Receiver,
     bool WaitForInitialSync) {
-  assert(!Path.empty() && "Path.empty()");
+  if (Path.empty())
+    llvm::report_fatal_error(
+        "DirectoryWatcher::create can not accept an empty Path.");
 
   const int InotifyFD = inotify_init1(IN_CLOEXEC);
   if (InotifyFD == -1)
Index: cfe/trunk/lib/DirectoryWatcher/mac/DirectoryWatcher-mac.cpp
===================================================================
--- cfe/trunk/lib/DirectoryWatcher/mac/DirectoryWatcher-mac.cpp
+++ cfe/trunk/lib/DirectoryWatcher/mac/DirectoryWatcher-mac.cpp
@@ -150,7 +150,8 @@
     StringRef Path,
     std::function<void(llvm::ArrayRef<DirectoryWatcher::Event>, bool)> Receiver,
     dispatch_queue_t Queue) {
-  assert(!Path.empty() && "Path.empty()");
+  if (Path.empty())
+    return nullptr;
 
   CFMutableArrayRef PathsToWatch = [&]() {
     CFMutableArrayRef PathsToWatch =
@@ -208,7 +209,10 @@
   dispatch_queue_t Queue =
       dispatch_queue_create("DirectoryWatcher", DISPATCH_QUEUE_SERIAL);
 
-  assert(!Path.empty() && "Path.empty()");
+  if (Path.empty())
+    llvm::report_fatal_error(
+        "DirectoryWatcher::create can not accept an empty Path.");
+
   auto EventStream = createFSEventStream(Path, Receiver, Queue);
   assert(EventStream && "EventStream expected to be non-null");
 
Index: cfe/trunk/unittests/DirectoryWatcher/DirectoryWatcherTest.cpp
===================================================================
--- cfe/trunk/unittests/DirectoryWatcher/DirectoryWatcherTest.cpp
+++ cfe/trunk/unittests/DirectoryWatcher/DirectoryWatcherTest.cpp
@@ -277,14 +277,20 @@
        {EventKind::Modified, "c"}}
       };
 
-  auto DW = DirectoryWatcher::create(
-      fixture.TestWatchedDir,
-      [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
-                      bool IsInitial) {
-        TestConsumer.consume(Events, IsInitial);
-      },
-      /*waitForInitialSync=*/true);
-  if (!DW) return;
+  llvm::Expected<std::unique_ptr<DirectoryWatcher>> DW =
+      DirectoryWatcher::create(
+          fixture.TestWatchedDir,
+          [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
+                          bool IsInitial) {
+            TestConsumer.consume(Events, IsInitial);
+          },
+          /*waitForInitialSync=*/true);
+  if (!DW) {
+    logAllUnhandledErrors(
+        DW.takeError(), llvm::errs(),
+        "DirectoryWatcherTest Failure on DirectoryWatcher::create(): ");
+    exit(EXIT_FAILURE);
+  }
 
   checkEventualResultWithTimeout(TestConsumer);
 }
@@ -309,14 +315,20 @@
        {EventKind::Modified, "c"}}
        };
 
-  auto DW = DirectoryWatcher::create(
-      fixture.TestWatchedDir,
-      [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
-                      bool IsInitial) {
-        TestConsumer.consume(Events, IsInitial);
-      },
-      /*waitForInitialSync=*/false);
-  if (!DW) return;
+  llvm::Expected<std::unique_ptr<DirectoryWatcher>> DW =
+      DirectoryWatcher::create(
+          fixture.TestWatchedDir,
+          [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
+                          bool IsInitial) {
+            TestConsumer.consume(Events, IsInitial);
+          },
+          /*waitForInitialSync=*/false);
+  if (!DW) {
+    logAllUnhandledErrors(
+        DW.takeError(), llvm::errs(),
+        "DirectoryWatcherTest Failure on DirectoryWatcher::create(): ");
+    exit(EXIT_FAILURE);
+  }
 
   checkEventualResultWithTimeout(TestConsumer);
 }
@@ -330,14 +342,20 @@
        {EventKind::Modified, "b"},
        {EventKind::Modified, "c"}}};
 
-  auto DW = DirectoryWatcher::create(
-      fixture.TestWatchedDir,
-      [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
-                      bool IsInitial) {
-        TestConsumer.consume(Events, IsInitial);
-      },
-      /*waitForInitialSync=*/true);
-  if (!DW) return;
+  llvm::Expected<std::unique_ptr<DirectoryWatcher>> DW =
+      DirectoryWatcher::create(
+          fixture.TestWatchedDir,
+          [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
+                          bool IsInitial) {
+            TestConsumer.consume(Events, IsInitial);
+          },
+          /*waitForInitialSync=*/true);
+  if (!DW) {
+    logAllUnhandledErrors(
+        DW.takeError(), llvm::errs(),
+        "DirectoryWatcherTest Failure on DirectoryWatcher::create(): ");
+    exit(EXIT_FAILURE);
+  }
 
   fixture.addFile("a");
   fixture.addFile("b");
@@ -356,14 +374,20 @@
       {{EventKind::Modified, "a"}},
       {{EventKind::Modified, "a"}}};
 
-  auto DW = DirectoryWatcher::create(
-      fixture.TestWatchedDir,
-      [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
-                      bool IsInitial) {
-        TestConsumer.consume(Events, IsInitial);
-      },
-      /*waitForInitialSync=*/true);
-  if (!DW) return;
+  llvm::Expected<std::unique_ptr<DirectoryWatcher>> DW =
+      DirectoryWatcher::create(
+          fixture.TestWatchedDir,
+          [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
+                          bool IsInitial) {
+            TestConsumer.consume(Events, IsInitial);
+          },
+          /*waitForInitialSync=*/true);
+  if (!DW) {
+    logAllUnhandledErrors(
+        DW.takeError(), llvm::errs(),
+        "DirectoryWatcherTest Failure on DirectoryWatcher::create(): ");
+    exit(EXIT_FAILURE);
+  }
 
   // modify the file
   {
@@ -387,14 +411,20 @@
       {{EventKind::Removed, "a"}},
       {{EventKind::Modified, "a"}, {EventKind::Removed, "a"}}};
 
-  auto DW = DirectoryWatcher::create(
-      fixture.TestWatchedDir,
-      [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
-                      bool IsInitial) {
-        TestConsumer.consume(Events, IsInitial);
-      },
-      /*waitForInitialSync=*/true);
-  if (!DW) return;
+  llvm::Expected<std::unique_ptr<DirectoryWatcher>> DW =
+      DirectoryWatcher::create(
+          fixture.TestWatchedDir,
+          [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
+                          bool IsInitial) {
+            TestConsumer.consume(Events, IsInitial);
+          },
+          /*waitForInitialSync=*/true);
+  if (!DW) {
+    logAllUnhandledErrors(
+        DW.takeError(), llvm::errs(),
+        "DirectoryWatcherTest Failure on DirectoryWatcher::create(): ");
+    exit(EXIT_FAILURE);
+  }
 
   fixture.deleteFile("a");
 
@@ -409,14 +439,20 @@
       {{EventKind::WatchedDirRemoved, ""},
        {EventKind::WatcherGotInvalidated, ""}}};
 
-  auto DW = DirectoryWatcher::create(
-      fixture.TestWatchedDir,
-      [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
-                      bool IsInitial) {
-        TestConsumer.consume(Events, IsInitial);
-      },
-      /*waitForInitialSync=*/true);
-  if (!DW) return;
+  llvm::Expected<std::unique_ptr<DirectoryWatcher>> DW =
+      DirectoryWatcher::create(
+          fixture.TestWatchedDir,
+          [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
+                          bool IsInitial) {
+            TestConsumer.consume(Events, IsInitial);
+          },
+          /*waitForInitialSync=*/true);
+  if (!DW) {
+    logAllUnhandledErrors(
+        DW.takeError(), llvm::errs(),
+        "DirectoryWatcherTest Failure on DirectoryWatcher::create(): ");
+    exit(EXIT_FAILURE);
+  }
 
   remove_directories(fixture.TestWatchedDir);
 
@@ -430,15 +466,21 @@
       {}, {{EventKind::WatcherGotInvalidated, ""}}};
 
   {
-    auto DW = DirectoryWatcher::create(
-        fixture.TestWatchedDir,
-        [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
-                        bool IsInitial) {
-          TestConsumer.consume(Events, IsInitial);
-        },
-        /*waitForInitialSync=*/true);
-    if (!DW) return;
+    llvm::Expected<std::unique_ptr<DirectoryWatcher>> DW =
+        DirectoryWatcher::create(
+            fixture.TestWatchedDir,
+            [&TestConsumer](llvm::ArrayRef<DirectoryWatcher::Event> Events,
+                            bool IsInitial) {
+              TestConsumer.consume(Events, IsInitial);
+            },
+            /*waitForInitialSync=*/true);
+    if (!DW) {
+      logAllUnhandledErrors(
+          DW.takeError(), llvm::errs(),
+          "DirectoryWatcherTest Failure on DirectoryWatcher::create(): ");
+      exit(EXIT_FAILURE);
+    }
   } // DW is destructed here.
 
   checkEventualResultWithTimeout(TestConsumer);
-}
\ No newline at end of file
+}