Cannot install Wave on Windows machine [NotImplementedError]

Hi everyone! :wave:

My very first post - it’s great to be here! :slight_smile:

I’ve an issue installing Wave on my Windows machine

I’ve followed the steps in the guide but I’ve got the following error:

    Welcome to the H2O Wave Interactive Tour!

     Go to http://localhost:10101/tour
    INFO:     Started server process [14140]
    INFO:     Waiting for application startup.
    INFO:     Application startup complete.
    INFO:     Uvicorn running on (Press CTRL+C to quit)
    INFO: - "POST / HTTP/1.1" 200 OK
    INFO: - "POST / HTTP/1.1" 200 OK
    Unhandled exception
    Traceback (most recent call last):
      File "c:\users\charly\desktop\wave\venv\lib\site-packages\h2o_wave\", line 265, in _process       
        await self._handle(q)
      File ".\examples\", line 193, in serve
        await show_example(q, catalog[route])
      File ".\examples\", line 162, in show_example
        await active_example.start()
      File ".\examples\", line 43, in start
        self.process = await asyncio.create_subprocess_exec(
      File "c:\program files\python38\lib\asyncio\", line 236, in create_subprocess_exec
        transport, protocol = await loop.subprocess_exec(
      File "c:\program files\python38\lib\asyncio\", line 1615, in subprocess_exec
        transport = await self._make_subprocess_transport(
      File "c:\program files\python38\lib\asyncio\", line 487, in _make_subprocess_transport       
        raise NotImplementedError
    Unhandled exception

INFO: - "POST / HTTP/1.1" 200 OK
An open stream object is being garbage collected; call "stream.close()" explicitly.

Any familiar with this issue?

I’ll keep trying and will post the solution here :slight_smile:


Yes, this a known issue with the tour (, not Wave itself: is a Wave app that launches other Wave apps, and it needs a fix for Windows.

We’ll look into it - thanks for reporting!


Thanks Prithvi! :pray:

Can I still visualise and use the code snippers that are in the tour section? If so, how?


Yes, you should be able to.

Run python examples\ for scripts.
Run wave run (or wave run examples\ for apps.

Each example is in its own .py file inside the examples directory.

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Great! That should do for now :slight_smile:

Do you have an ETA for that fix in Windows?


We have a PR open: Should be merged in a day or so.

It’ll replace the current examples/ with this file.

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