relocation R_WASM_MEMORY_ADDR_TLS_SLEB cannot be used against an undefined symbol `__wasm_lpad_context`

[alepvn33]

Hello all, I am trying to compile a large C++ codebase to WASM.
Exception handling (throw, catch) is being used, as well as pthreads.

I am compiling the code with WASI SDK 24.0 release using these flags:

```
-DCMAKE_C_COMPILER="/opt/wasi-sdk/bin/clang" -DCXX_EXTRA="-Oz -g" -DCMAKE_CXX_COMPILER="/opt/wasi-sdk/bin/clang++" \
-DCMAKE_CXX_FLAGS="--target=wasm32-wasi-threads -pthread -fwasm-exceptions \
-gpubnames -D_WASI_EMULATED_PROCESS_CLOCKS -lwasi-emulated-process-clocks -D_WASI_EMULATED_SIGNAL \
-lwasi-emulated-signal -D_WASI_EMULATED_MMAN -D_WASI_EMULATED_GETPID -lwasi-emulated-getpid -Wno-everything \
-Wl,-z,stack-size=16777216 -Wl,--initial-memory=33554432,--no-check-features"  \
 -DCMAKE_C_FLAGS="--target=wasm32-wasi-threads -pthread -fwasm-exceptions" && \

As you can see, I am using -fwasm-exceptions and -pthread flags, nevertheless I am getting a compiling error:

`relocation R_WASM_MEMORY_ADDR_TLS_SLEB cannot be used against an undefined symbol `__wasm_lpad_context``

Why is this? I have read in other issues that WASI SDK should have exception handling support by now.

Thanks for your help.

[whitequark]

Exception handling (throw, catch) is being used, as well as pthreads.

My understanding as someone who is a WASI SDK user but not an expert is that -fwasm-exceptions + -pthread is currently not a supported configuration.