how can I debug function signature mismatch ?

I have an application that uses pthreads, and when I build with ```-s PROXY_TO_PTHREAD```

I get the following runtime error :
```
Uncaught RuntimeError: null function or function signature mismatch
at _do_call (Runtime.wasm:0xa738cb)
at emscripten_current_thread_process_queued_calls (Runtime.wasm:0xa724bd)
at emscripten_main_thread_process_queued_calls (Runtime.wasm:0xa74c49)
at ret. (Runtime.js:18705:24)
at Runtime.js:1649:20
at Worker.worker.onmessage (Runtime.js:2064:5)
```

I don't even know where it fails. anyone has any idea on how I can debug it ?

program is linked with the following link options :
```
"-O3", "-s SAFE_HEAP", "-s ASSERTIONS=1","-s ALLOW_MEMORY_GROWTH=1", "-s PTHREAD_POOL_SIZE=3", "-s ASYNCIFY", "-pthread", "-s ASYNCIFY_IMPORTS=['doLoadLibrary']","-s ALLOW_TABLE_GROWTH", "-s USE_PTHREADS=1", "-s PROXY_TO_PTHREAD", "-s EXPORTED_RUNTIME_METHODS=['FS']", "-s DYNCALLS=1","-s MAIN_MODULE=1", "-s USE_WEBGL2=1", "-s FULL_ES3=1", "-s OFFSCREEN_FRAMEBUFFER=1","-s FORCE_FILESYSTEM=1", "--profiling", "--pre-js="
```