Bug fix, use the home directory.

Author: david-cattermole

python/mmSolver/_api/collection.py

@@ -682,8 +682,9 @@ def _compile(self, prog_fn=None, status_fn=None):
             debug_file = maya.cmds.file(query=True, sceneName=True)
             debug_file = os.path.basename(debug_file)
             debug_file, ext = os.path.splitext(debug_file)
+            # TODO: Find a way to set the default directory path.
             debug_file_path = os.path.join(
-                os.path.expanduser('${HOME}'),
+                os.path.expanduser('~/'),
                 debug_file + '_' + str(i).zfill(6) + '.log')
             if len(debug_file) > 0 and debug_file_path is not None:
                 kwargs['debugFile'] = debug_file_path