Tomas Olvecky (Jan 13 2025 at 13:44): Tomas Olvecky (Jan 13 2025 at 13:44):I have enabled wasmtime::WasmBacktraceDetails and I can see the stack trace with files and line numbers, but only when the guest traps.
I did not succeed producing a detailed stack trace when the guest calls a host function. I tried returning an Err variant, but the caller (guest) file and line number is missing. The host function is defined using LinkerInstance.html#method.func_new_async.
Is it a bug, a limitation or is there another way to obtain the stack trace with line numbers from a host function?
Alex Crichton (Jan 13 2025 at 15:25):I forget exactly where this happens but if you're not seeing a backtrace on Err then I suspect we only auto-capture backtraces on traps. You can use WasmBacktrace::capture though (or force_capture) to do the same programmatically though
Tomas Olvecky (Jan 13 2025 at 17:40):Thanks @Alex Crichton , the WasmBacktrace was the right direction. I was looking at {err:?}, but one needs to use error.downcast_ref::<WasmBacktrace>().
Last updated: Jan 24 2025 at 00:11 UTC