Index: test/Driver/no-canonical-prefixes.c
===================================================================
--- test/Driver/no-canonical-prefixes.c
+++ test/Driver/no-canonical-prefixes.c
@@ -1,9 +1,14 @@
 // Due to ln -sf:
 // REQUIRES: shell
+// RUN: rm -rf %t.real
 // RUN: mkdir -p %t.real
 // RUN: cd %t.real
 // RUN: ln -sf %clang test-clang
 // RUN: cd ..
+// Important to remove %t.fake: If it already is a symlink to %t.real when
+// `ln -sf %t.real %t.fake` runs, then that would symlink %t.real to itself,
+// forming a cycle.
+// RUN: rm -rf %t.fake
 // RUN: ln -sf %t.real %t.fake
 // RUN: cd %t.fake
 // RUN: ./test-clang -v -S %s 2>&1 | FileCheck --check-prefix=CANONICAL %s