[libcxx] r347435 - [libcxx] Improve error message when an invalid directory is provided as use_system_cxx_lib

[Louis Dionne]

Author: ldionne
Date: Wed Nov 21 15:00:45 2018
New Revision: 347435

URL: http://llvm.org/viewvc/llvm-project?rev=347435&view=rev
Log:
[libcxx] Improve error message when an invalid directory is provided as use_system_cxx_lib

Modified:
    libcxx/trunk/utils/libcxx/test/config.py

Modified: libcxx/trunk/utils/libcxx/test/config.py
URL: http://llvm.org/viewvc/llvm-project/libcxx/trunk/utils/libcxx/test/config.py?rev=347435&r1=347434&r2=347435&view=diff
==============================================================================
--- libcxx/trunk/utils/libcxx/test/config.py (original)
+++ libcxx/trunk/utils/libcxx/test/config.py Wed Nov 21 15:00:45 2018
@@ -307,7 +307,7 @@ class Configuration(object):
         elif self.use_system_cxx_lib == 'false':
             self.use_system_cxx_lib = False
         elif self.use_system_cxx_lib:
-            assert os.path.isdir(self.use_system_cxx_lib)
+            assert os.path.isdir(self.use_system_cxx_lib), "the specified use_system_cxx_lib parameter (%s) is not a valid directory" % self.use_system_cxx_lib
         self.lit_config.note(
             "inferred use_system_cxx_lib as: %r" % self.use_system_cxx_lib)