Rework error handling in temp dirs

Author: Kevin D Smith

cicd/tar2conda.py

@@ -185,7 +185,10 @@ def __enter__(self):
 
     def __exit__(self, exc_type, exc_value, traceback):
         import atexit
-        atexit.register(shutil.rmtree, self.dir_name)
+        def onerror(func, path, excinfo):
+            ''' Error function for rmtree '''
+            print_err('WARNING: Could not remove file %s.' % path)
+        atexit.register(shutil.rmtree, self.dir_name, onerror=onerror)
 
 
 @contextlib.contextmanager