Please include the following in your bug report:

Version of emscripten/emsdk:
emcc (Emscripten gcc/clang-like replacement + linker emulating GNU ld) 3.1.34 (57b21b8)
clang version 17.0.0 (https://github.com/llvm/llvm-project a031f72187ce495b9faa4ccf99b1e901a3872f4b)
Target: wasm32-unknown-emscripten
Thread model: posix
InstalledDir: D:\emsdk\upstream\bin

Failing command line in full:
worker.js onmessage() captured an uncaught exception: RuntimeError: table index is out of bounds

i'm trying to spawn a function defined in dynamical library.but I always get table index outof bounds, what are the alternatives? or is it simply impossible?

the defined function is not called by any other threads but this one, and the thread is immediately joined, the function is doing harmless things none other than calculations and printing stuff, there's no harmful api calls at all, this should be possible in the web sandbox since it can set the PC to the corresponding symbol start. but it seems the access is restricted.