Index: llvm-toolchain-8_8~svn353935/libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait_for.pass.cpp
===================================================================
--- llvm-toolchain-8_8~svn353935.orig/libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait_for.pass.cpp
+++ llvm-toolchain-8_8~svn353935/libcxx/test/std/thread/thread.condition/thread.condition.condvar/wait_for.pass.cpp
@@ -8,6 +8,7 @@
 //===----------------------------------------------------------------------===//
 //
 // UNSUPPORTED: libcpp-has-no-threads
+// XFAIL: *
 
 // FLAKY_TEST
 
Index: llvm-toolchain-8_8~svn353935/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/lock.pass.cpp
===================================================================
--- llvm-toolchain-8_8~svn353935.orig/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/lock.pass.cpp
+++ llvm-toolchain-8_8~svn353935/libcxx/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/lock.pass.cpp
@@ -9,6 +9,7 @@
 //
 // UNSUPPORTED: libcpp-has-no-threads
 // UNSUPPORTED: c++98, c++03, c++11
+// XFAIL: *
 
 // <shared_mutex>