More explicit error message

subprocess2.py

Index: subprocess2.py
diff --git a/subprocess2.py b/subprocess2.py
index 716ef20faed48ffc9866e5da77a5207927bf857d..6e407926b94359385c31b9f9dc7f4fb1898f16d7 100644
--- a/subprocess2.py
+++ b/subprocess2.py
@@ -248,8 +248,9 @@ class Popen(subprocess.Popen):
             'to learn how to fix this error; you need to rebase your cygwin '
             'dlls')
       # Popen() can throw OSError when cwd or args[0] doesn't exist.
-      raise OSError('%s or %s probably doesn\'t exist' %
-                    (kwargs.get('cwd'), args[0]))
+      raise OSError('Execution failed with error: %s.\n'
+                    'Check that %s or %s exist and have execution permission.'

[M-A Ruel, 2014/04/29 17:19:23]

optional: if you want to be more helpful, you could call os.path.isfile() first,
then os.access(, os.X_OK) and change the message accordingly.

[pgervais, 2014/04/29 17:26:58]

That would indeed be cleaner, but str(e) gives that information already. 

+                    % (str(e), kwargs.get('cwd'), args[0]))
 
   def _tee_threads(self, input):  # pylint: disable=W0622
     """Does I/O for a process's pipes using threads.