This topic has an OP identical to yours, by an account that made that topic and did nothing else. The answer from that topic should still apply[1]: Cross-Compiling a Rust Library with DuckDB for WebAssembly (WASM) - #2 by hax10.
Also, you could try using the "bundled" feature to compile DuckDB from source, but I don't know whether it would work compiling to WASM.
since it's the same question ↩︎