Index: lldb/test/API/lit.cfg.py
===================================================================
--- lldb/test/API/lit.cfg.py
+++ lldb/test/API/lit.cfg.py
@@ -123,6 +123,7 @@
             )
 
     if "Thread" in config.llvm_use_sanitizer:
+        config.environment["TSAN_OPTIONS"] = "halt_on_error=1"
         if "Darwin" in config.host_os:
             config.environment["DYLD_INSERT_LIBRARIES"] = find_sanitizer_runtime(
                 "libclang_rt.tsan_osx_dynamic.dylib"
Index: lldb/test/Shell/lit.cfg.py
===================================================================
--- lldb/test/Shell/lit.cfg.py
+++ lldb/test/Shell/lit.cfg.py
@@ -48,6 +48,10 @@
     ]
 )
 
+# Enable sanitizer runtime flags.
+config.environment["ASAN_OPTIONS"] = "detect_stack_use_after_return=1"
+config.environment["TSAN_OPTIONS"] = "halt_on_error=1"
+
 # Support running the test suite under the lldb-repro wrapper. This makes it
 # possible to capture a test suite run and then rerun all the test from the
 # just captured reproducer.