Help with debugging wasm and page generated with Emscripten 3.1.68

[netolcc06]

Hi everyone,

I'd like to have some guidance on how to properly debug one issue I'm having.

A few months ago I worked on using Emscripten to generate a wasm version of cvc5. At that time I was using Emscripten v3.1.18 and managed to produce successful builds and pages by setting the HTML option. Flags such as -s EXPORTED_RUNTIME_METHODS='["ccall","cwrap"]' -s ENVIRONMENT=web -s EXPORTED_FUNCTIONS=_main -s INVOKE_RUN=1 -s EXIT_RUNTIME=0 -s INCOMING_MODULE_JS_API=argument also worked fine.

Recently I tried to use Emscripten 3.1.68 with the same flags, but the generated page just throws a generic message Uncaught (in promise) 868912 when it starts. I thought the issue could be related to changes in cvc5's build system, but nothing has changed there - and old versions of the program that used to produce valid wasm + html pages present the same behaviour if built with 3.1.68. From what I checked from Emscripten docs, compilation instructions seem to be the same as a few months back though.

With that said, what is the best way of moving forward here and debug what is happening with the page? I want to figure out what actually got broken with the most recent version and adjust my source code, if necessary, in order to produce valid wasm binaries.

Thanks in advance!

[kripken]

For a regression like this, bisection is often a fast way to find what caused the issue.

[sbc100]

Also, building with without optimization (i.e. with -O0 which is the default) and/or with -sASSERTIONS can help a lot.

When you get the Uncaught (in promise) I would expect some kind of backtrace that might give you a clue as to what the issue is.