ERROR - Unexpected error during query execution (Connection: not acquired): 'SafeConnection' object has no attribute '_reader'
Traceback (most recent call last):
File "/home/user/mariadb-mcp/src/server.py", line 259, in _execute_query
async with self.pool.acquire() as conn:
File "/home/user/mariadb-mcp/.venv/lib/python3.11/site-packages/asyncmy/contexts.py", line 75, in __aenter__
self._conn = await self._coro
^^^^^^^^^^^^^^^^
File "asyncmy/pool.pyx", line 118, in _acquire
File "asyncmy/pool.pyx", line 120, in asyncmy.pool.Pool._acquire
File "/home/user/mariadb-mcp/src/custom_connection.py", line 72, in fill_free_pool
if conn._reader.at_eof() or conn._reader.exception():
^^^^^^^^^^^^
AttributeError: 'SafeConnection' object has no attribute '_reader'
2026-08-07 12:07:48,816 - config - ERROR - TOOL ERROR: list_databases failed: An unexpected error occurred: 'SafeConnection' object has no attribute '_reader'
Traceback (most recent call last):
File "/home/user/mariadb-mcp/src/server.py", line 259, in _execute_query
async with self.pool.acquire() as conn:
File "/home/user/mariadb-mcp/.venv/lib/python3.11/site-packages/asyncmy/contexts.py", line 75, in __aenter__
self._conn = await self._coro
^^^^^^^^^^^^^^^^
File "asyncmy/pool.pyx", line 118, in _acquire
File "asyncmy/pool.pyx", line 120, in asyncmy.pool.Pool._acquire
File "/home/user/mariadb-mcp/src/custom_connection.py", line 72, in fill_free_pool
if conn._reader.at_eof() or conn._reader.exception():
^^^^^^^^^^^^
AttributeError: 'SafeConnection' object has no attribute '_reader'
The above exception was the direct cause of the following exception:
Traceback (most recent call last):
File "/home/user/mariadb-mcp/src/server.py", line 379, in list_databases
results = await self._execute_query(sql)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/user/mariadb-mcp/src/server.py", line 295, in _execute_query
raise RuntimeError(f"An unexpected error occurred: {e}") from e
I can confirm that downgrading asyncmy to 0.2.11 "solves" the problem, so the issue must be caused by recent changes to asyncmy.
Recent commits in asyncmy (https://github.com/long2ice/asyncmy/commits/main) have changed internal connection fields accessed by MariaDB MCP. The MCP server starts up, but any tool call generates the following exception:
I can confirm that downgrading asyncmy to 0.2.11 "solves" the problem, so the issue must be caused by recent changes to asyncmy.