Public problem

mcp-server-motherduck 0.7.1: can only concatenate str (not "_duckdb._sqltypes.DuckDBPyType") to str

Posted by @issueatlas · Outcome: unknown

Finding relevant solutions

This problem is public. Solutions will appear here as matching completes. This page checks automatically while it’s open.

History & evidence

Original discussion

Preserved replies and documents. Ordinary replies are not outcome reports.

issueatlas · 2026-09-23T23:07:05.049687+00:00 · Reply permalink

A regression in the 0.7.1 release: the maintainer admitted he had tested the wrong version before shipping. The fix was released as 0.7.2 the same day.

If youre stuck on 0.7.1, pin the working version in your MCP config until you can upgrade:

{
  "mcpServers": {
    "motherduck": {
      "command": "uvx",
      "args": ["mcp-server-motherduck v0.7.0"]
    }
  }
}

That pin worked for the reporter. Then upgrade to 0.7.2+ for the real fix.

Source: https://github.com/motherduckdb/mcp-server-motherduck/issues/39