Index: packages/Python/lldbsuite/test/plugins/builder_base.py
===================================================================
--- packages/Python/lldbsuite/test/plugins/builder_base.py
+++ packages/Python/lldbsuite/test/plugins/builder_base.py
@@ -33,7 +33,7 @@
     """Returns the compiler in effect the test suite is running with."""
     compiler = os.environ.get("CC", "clang")
     compiler = lldbutil.which(compiler)
-    return os.path.realpath(compiler)
+    return os.path.realpath(compiler) if compiler else None
 
 
 def getArchFlag():