Added graceful handling of the directory structure changing during a 'walk'.

fs/base.py

@@ -712,6 +712,7 @@ class FS(object):
             while dirs:
                 current_path = dirs.pop()
                 paths = []
+                try:
                     for filename in listdir(current_path):
                         path = pathjoin(current_path, filename)
                         if self.isdir(path):                        
@@ -720,15 +721,22 @@ class FS(object):
                         else:                        
                             if wildcard(filename):
                                 paths.append(filename)
+                except ResourceNotFoundError:
+                    # Could happen if another thread / process deletes something whilst we are walking
+                    pass
                             
                 yield (current_path, paths)
 
         elif search == "depth":
 
             def recurse(recurse_path):
+                try:
                     for path in listdir(recurse_path, wildcard=dir_wildcard, full=True, dirs_only=True):
                         for p in recurse(path):
                             yield p
+                except ResourceNotFoundError:
+                    # Could happen if another thread / process deletes something whilst we are walking
+                    pass
                 yield (recurse_path, self.listdir(recurse_path, wildcard=wildcard, files_only=True))
 
             for p in recurse(path):