diff --git a/libcxx/utils/libcxx/test/newformat.py b/libcxx/utils/libcxx/test/newformat.py
--- a/libcxx/utils/libcxx/test/newformat.py
+++ b/libcxx/utils/libcxx/test/newformat.py
@@ -240,4 +240,6 @@
         script = lit.TestRunner.applySubstitutions(script, substitutions,
                                                    recursion_limit=recursiveExpansionLimit)
 
+        test.config.environment = dict(os.environ)
+
         return lit.TestRunner._runShTest(test, litConfig, useExternalSh, script, tmpBase)