diff --git a/libcxx/utils/libcxx/test/config.py b/libcxx/utils/libcxx/test/config.py
--- a/libcxx/utils/libcxx/test/config.py
+++ b/libcxx/utils/libcxx/test/config.py
@@ -159,7 +159,6 @@
         self.lit_config.note("Running against the C++ Library at {}".format(self.cxx_runtime_root))
         self.lit_config.note("Linking against the ABI Library at {}".format(self.abi_library_root))
         self.lit_config.note("Running against the ABI Library at {}".format(self.abi_runtime_root))
-        sys.stderr.flush()  # Force flushing to avoid broken output on Windows
 
     def get_test_format(self):
         from libcxx.test.format import LibcxxTestFormat
diff --git a/llvm/utils/lit/lit/LitConfig.py b/llvm/utils/lit/lit/LitConfig.py
--- a/llvm/utils/lit/lit/LitConfig.py
+++ b/llvm/utils/lit/lit/LitConfig.py
@@ -169,6 +169,11 @@
         line = inspect.getlineno(f)
         sys.stderr.write('%s: %s:%d: %s: %s\n' % (self.progname, file, line,
                                                   kind, message))
+        if self.isWindows:
+            # In a git bash terminal, the writes to sys.stderr aren't visible
+            # on screen immediately. Flush them here to avoid broken/misoredered
+            # output.
+            sys.stderr.flush()
 
     def note(self, message):
         if not self.quiet: