DuckDB extension cannot be loaded.

[Banbury]

When I start the MCP server (0.15.0) with uvx mcp-server-ladybug --db-path :memory:. I get the following error message:

Traceback (most recent call last):
  File "<frozen runpy>", line 198, in _run_module_as_main
  File "<frozen runpy>", line 88, in _run_code
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Scripts\mcp-server-ladybug.exe\__main__.py", line 10, in <module>
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Lib\site-packages\click\core.py", line 1485, in __call__
    return self.main(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Lib\site-packages\click\core.py", line 1406, in main
    rv = self.invoke(ctx)
         ^^^^^^^^^^^^^^^^
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Lib\site-packages\click\core.py", line 1269, in invoke
    return ctx.invoke(self.callback, **ctx.params)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Lib\site-packages\click\core.py", line 824, in invoke
    return callback(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Lib\site-packages\mcp_server_ladybug\__main__.py", line 123, in main
    server, initialization_options = build_application(
                                     ^^^^^^^^^^^^^^^^^^
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Lib\site-packages\mcp_server_ladybug\server.py", line 28, in build_application
    db_client = DatabaseClient(
                ^^^^^^^^^^^^^^^
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Lib\site-packages\mcp_server_ladybug\database.py", line 17, in __init__
    self.conn = self._initialize_connection()
                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Lib\site-packages\mcp_server_ladybug\database.py", line 34, in _initialize_connection
    conn.execute("LOAD duckdb")
  File "C:\Users\micke\AppData\Local\uv\cache\archive-v0\q0WdNBwI25YXkYb1lz6RU\Lib\site-packages\real_ladybug\connection.py", line 131, in execute
    query_result_internal = self._connection.query(query)
                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: IO exception: Failed to load library: C:\Users\*****/.lbdb/extension/0.15.0/win_amd64/duckdb/libduckdb.lbug_extension which is needed by extension: duckdb.

[adsharma]

0.15.0 had a bug with extensions. Fixed in 0.15.1

uvx mcp-server-ladybug --db-path :memory:
Installed 32 packages in 54ms
Starting LadybugDB MCP Server v0.1.0
Transport: stdio
Database: :memory:
Max rows: 1024, Max chars: 50000

[ladybug] INFO - Starting LadybugDB MCP Server
[ladybug] INFO - Connecting to Ladybug database at: :memory:
[ladybug] INFO - Loading DuckDB extensions: json
[ladybug] INFO - Loading DuckDB extensions: duckdb
[ladybug] INFO - Successfully connected to Ladybug database
[ladybug] INFO - Registering handlers

[Banbury]

I guess, you have to update the dependency then.

[adsharma]

I did. That's why I had to bump up the release version to 0.15.1 and update the extension dependency from 0.14.0 -> 0.15.0

All 0.15.x releases will access the 0.15.0 extensions (we guard against ABI changes within a minor release).

[Banbury]

@adsharma What's wrong is the dependency in the MCP server. It's still using 0.15.0 of Ladybug. Closing the ticket, doesn't change that.

[adsharma]

I searched the repo. The string 0.15.0 doesn't appear anywhere. The version we have is >=0.14.0 as seen here.

My guess is that you built something before the 0.15.1 release. Suggestion is to delete your pip cache and rebuild.

[Banbury]

I have used this server, Ladybug, and DuckDB for the first time today. I haven't even built anything. All I did was starting the server with uvx, as it says in the docu.
Purging the pip cache changed nothing.
Are you on Windows or Linux?

[adsharma]

I use all 3 platforms, but mostly WSLv2 on Windows. For uv

uv cache clean
OR
uvx --no-cache ...

[Banbury]

I've tried with --no-cache and it makes no difference. Still the same error.