The DuckDB MCP server broke when pandas 2.3.0 came out, because pandas 2.3.0 failed to build on some platforms. Users on macOS ARM hit it hardest, and pinning pandas==2.2.3 via uvx worked as a workaround. The PyPI install of mcp-server-motherduck doesnt honor a lockfile, so it pulled the broken pandas and the server wouldnt start.
mcp-server-motherduck broken by pandas 2.3.0 (wont build on macOS ARM)
The maintainer's take: pandas was only used for output formatting and was causing more problems than it solved. He shipped 0.5.1 which removes the pandas dependency problem.
Workarounds if youre on an older version:
uvx --with 'pandas==2.2.3' mcp-server-motherduckThat pins the last good pandas and worked on Apple Silicon. Or sidestep pandas entirely with a non-pandas result format:
uvx mcp-server-motherduck --db-path md: --result-format duckboxUpgrading to 0.5.1+ is the real fix.
Source: https://github.com/motherduckdb/mcp-server-motherduck/issues/24
Source: https://github.com/motherduckdb/mcp-server-motherduck/issues/24