Index: test/FileCheck/lit.local.cfg
===================================================================
--- /dev/null
+++ test/FileCheck/lit.local.cfg
@@ -0,0 +1,8 @@
+# Remove FILECHECK_DUMP_INPUT_ON_FAILURE from environment
+# because the tests expect that environment variable is
+# normally unset.
+file_check_dump_env_var = 'FILECHECK_DUMP_INPUT_ON_FAILURE'
+if file_check_dump_env_var in config.environment:
+  lit_config.note('Removing {} from environment for FileCheck tests'.format(
+    file_check_dump_env_var))
+  config.environment.pop(file_check_dump_env_var)