Unable to build latest on macOS Mojave withabout box2d.js

[mysterycommand]

Unable to build latest on macOS Mojave with [email protected]

[kripken]

To fix that error, the error message suggests this, which should work:

warning: To disable errors for undefined symbols use `-s ERROR_ON_UNDEFINED_SYMBOLS=0`

What you suggest about just running WebAssembly.instantiateStreaming would work for pure wasm, but not for the JS that works with it. In some cases you can get close to not having any JS, see here, but until wasm has access to JS objects it will depend on JS heavily for a lot of things.

[mysterycommand]

Hey, thanks for getting back to me! I'll give that a try. I didn't initially because disable errors sounds a little like suppress errors and I was hoping there would be an obvious way to actually fix them?

Anyway, I'll give that a try and do a bit more reading about how importObject and JS/WASM interop works.

[kripken]

Yeah, fixing the errors would be better, if you or someone has time to look into them. (Maybe a file isn't linked in, for example?) But that option would get us to the same behavior emscripten had before, so it's not making things worse.

[mysterycommand]

Okay, I forked this and created a branch that you can see in this comparison. I broke the LINK_OPTS out to multiple lines so they'd be a little easier to read and added the -s ERROR_ON_UNDEFINED_SYMBOLS=0 like you suggested.

Running $ /Users/matt/Sites/juj/emsdk/emscripten/1.38.16/emmake make VERSION=latest does generate a new build/Box2D_v2.3.1_min.wasm file, but that's it … the output ends with:

11 error(s), 5 warning(s)
ERROR:root:closure compiler failed (rc: 11)
make: *** [box2d.js] Error 1

There are several giant blocks of what looks like minified JavaScript with what look like more specific error messages in there … they look like this:

                                                                                                                                               ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

/tmp/tmpma5o38/Box2D_v2.3.1_min.bc.o.js.pp.js.mem.js.jso.js.jso.js.jso.js:1: ERROR - variable _emscripten_bind_b2Vec3_b2Vec3_2 is undeclared

… but there's several thousand lines between them and my grep juju is failing me right now.

As far as actually fixing the errors I'd be happy to try and figure this out, but any pointers as to where they'd need to be linked in? This whole set up is new to me and between the Python and the C++ and the generated files and the IDLs and the make scripts … I'm kinda lost. I am fully willing to accept that I may be trying to bite off more than i can chew.

[kripken]

Closure compiler issues like that are tricky to debug in my experience. But you can build without closure and look for why that function isn't defined - it should be emitted from the webidl binder emitter, I think, so it's not a linking problem.

It's possible this isn't a bug here, but in the upstream webidl binder emitter - if you can get a standalone testcase showing the issue that could prove that.

However, another option is to set -s IGNORE_CLOSURE_COMPILER_ERRORS=1 to ignore those.