Build the extension

[jtpio]

Continuation of #3

[jtpio]

OK so it now builds on CI and loads as a federated extension:

Need to check how we can properly bundle the emscripten generated files now.

[DerThorsten]

awesome!
maybe we can use the Modules locateFile https://emscripten.org/docs/api_reference/module.html#Module.locateFile
With that one can overwrite the xeus_lua.wasm path.

[DerThorsten]

https://github.com/DerThorsten/jupyterlite_xeus_lua/blob/3a22e56672ef5aca0655fc64aaa39fac74e5b6a2/src/worker.ts#L45 I think this is where one can add the locateFile function

[jtpio]

Nice. Sounds like we should be able to use it indeed.

[jtpio]

Getting the following when starting the kernel:

[DerThorsten]

@jtpio which browser are you using? I give it a try in a few minutes.
For firefox I would not be surprised

[jtpio]

Looks like it's for both Firefox 94.0b2 (developer edition) and Chromium 94.

@DerThorsten do you still have the link to the previous demo (the JupyterLite fork)? To see if we hit the same code path as here:

[DerThorsten]

No the page was removed when I transferd the repo from my accound to jupyter-xeus I think.
But I have one locally
lab.zip

[jtpio]

OK I was wondering whether the emscripten compile flags had changed in between

[DerThorsten]

@jtpio I just tried to build your changes on my machine but I am facing this:

(jupyterlite-xeus-lua) ➜  jupyterlite_xeus_lua git:(518fbfc) jlpm run build
yarn run v1.21.1
$ jlpm run build:lib && jlpm run copy-files && jlpm run build:labextension:dev
$ tsc
src/xeus_server_kernel.ts:23:66 - error TS2339: Property 'url' does not exist on type 'ImportMeta'.

23     this._worker = new Worker(new URL('./worker.js', import.meta.url));
                                                                    ~~~


Found 1 error.

EDIT: lets me try the steps as they are in the CI workflow..sry for potential spam =)
EDIT: Ok works...forget the "jlpm" command

[jtpio]

Also you might want to clean some stuff up locally with:

rm -rf node_modules
jlpm
jlpm clean:all
jlpm run build

[DerThorsten]

@jtpio fyi, when I start the kernel I am getting this error on chrome:

Uncaught (in promise) TypeError: Cannot read property 'startsWith' of undefined
    at isDataURI (extensions/jupyterlite-xeus-lua/static/lib_worker_js.6e9b528aeb6504d42281.js:1065)
    at instantiateAsync (extensions/jupyterlite-xeus-lua/static/lib_worker_js.6e9b528aeb6504d42281.js:1149)
    at createWasm (extensions/jupyterlite-xeus-lua/static/lib_worker_js.6e9b528aeb6504d42281.js:1174)
    at extensions/jupyterlite-xeus-lua/static/lib_worker_js.6e9b528aeb6504d42281.js:7550
    at loadCppModule (extensions/jupyterlite-xeus-lua/static/lib_worker_js.6e9b528aeb6504d42281.js:56)
    at Object../lib/worker.js (extensions/jupyterlite-xeus-lua/static/lib_worker_js.6e9b528aeb6504d42281.js:84)
    at __webpack_require__ (extensions/jupyterlite-xeus-lua/static/lib_worker_js.6e9b528aeb6504d42281.js:8608)
    at extensions/jupyterlite-xeus-lua/static/lib_worker_js.6e9b528aeb6504d42281.js:8710
    at extensions/jupyterlite-xeus-lua/static/lib_worker_js.6e9b528aeb6504d42281.js:8712

[DerThorsten]

@jtpio fyi with firefox I also see the "SharedArrayBuffer" thing

[DerThorsten]

ok, the reason for the error above is that the locateFile function does not return anything =)

[jtpio]

when I start the kernel I am getting this error on chrome:

Which version is it? Wondering whether this might be related to recent updates: https://developer.chrome.com/blog/enabling-shared-array-buffer/

[DerThorsten]

Version 91.0.4472.114 (Official Build) (64-bit)

[jtpio]

Ah that could explain why if these SharedArrayBuffer changes went into 92...

[jtpio]

Maybe there is an emscripten flag what would help avoid generating code using it? Or is it required to be able to compile xeus?

[DerThorsten]

@jtpio I think this is required if we compile xeus with threads and for the widgets I think we need that.

btw when I copy the wasm file to _ouput/ /lab/extensions/jupyterlite-xeus-lua/static/xeus_lua.wasm everything works.
If I do not copy the file I get bizzare error messages!
(after removing the empty locateFile).

So maybe we should just use the CopyPlugin trick

[DerThorsten]

when I copy the wasm file by hand

[jtpio]

btw when I copy the wasm file to _ouput/ /lab/extensions/jupyterlite-xeus-lua/static/xeus_lua.wasm everything works.

Ah nice so the wasm file is loaded correctly even without the custom locateFile?

[DerThorsten]

@jtpio yes! (but again, after coping by hand :) )

[jtpio]

Marked as ready if you would like to get that in already, and then we continue in another PR (with the file copy trick)

[jtpio]

It would be fine to do the copy for now if that's the only way.

Maybe we could then try to get webpack to do it automatically using the asset modules and constructing a new URL pointing the .wasm file.

Still, we need to check how to handle this SharedArrayBuffer issue.

[DerThorsten]

@jtpio once we have a running setup I can experiment around how to get ride of this / how to handle this