Blazor browser crashes

[connor4312]

Hi, I came here from https://devblogs.microsoft.com/aspnet/blazor-webassembly-3-2-0-preview-3-release-now-available/
And seems like pwa-msedge doesn't work.
I have latest MS Edge installed ( Version 80.0.361.69 (Official build) (64-bit) ) "debug.javascript.usePreview": true and this is my launch.json:

{
            "name": ".NET Core Debug Blazor Web Assembly in Edge",
            "type": "pwa-msedge",
            "request": "launch",
            "timeout": 30000,
            "url": "https://localhost:5001",
            "webRoot": "${workspaceFolder}/Server",
            "inspectUri": "{wsProtocol}://{url.hostname}:{url.port}/_framework/debug/ws-proxy?browser={browserInspectUri}"
}

When I trying to start debug I see this error:

Unable to launch browser: "Failed to launch browser!
[0327/171300.005:ERROR:file_io.cc(89)] ReadExactly: expected 120, observed 40

TROUBLESHOOTING: https://github.com/GoogleChrome/puppeteer/blob/master/docs/troubleshooting.md

Can you help me find out what's wrong?

_Originally posted by @vchirikov in microsoft/vscode-js-debug#405

I've been getting a steady trickle of reports on this from people using Blazor, reported on both Chrome and Edge. @digeff reports that they haven't seen this on VS, and I haven't received reports on this from any non-Blazor users. Is there anything Blazor is doing differently that could cause this? Trees to bark up would also be appreciated 😛

[captainsafia]

@connor4312 The debugging setup in Blazor is definitely a little different than a standard JS debugging experience.

I'm a little surprised at the exception thrown here. It seems to be coming from the Chrome launcher itself, which comes into play before the Blazor app has launched. The entire flow for debugging Blazor WASM in VS Code looks something like this (assuming the user uses blazorwasm debug type).

1. User presses F5.
2. VS Code passes the debugging request to our debugging config resolver.
3. The blazorwasm config provider spawns a process running dotnet run in the current working directory (or a cwd provided by the user).
4. The blazorwasm config provider starts a JS debugging session throw either pwa-msedge or pwa-chrome.
5. The JS debugger sends a request to http://localhost:5001/_framework/debug/ws-proxy/...
6. The Blazor server receives the request from HelloConsole folder does not exist. The actual folder name is ConsoleApp... #5 and starts the Mono debug proxy. The JS debugger sends CDP messages to this endpoint.
7. The Chrome browser is started.

You might have some more insights, @connor4312, about the exact ordering of 5-7. Perhaps the fact that the JS debugger communicates with the application server causes some issues here? Although I dunno why that would surface the stack traces we are seeing from Chrome.

[connor4312]

It seems like we haven't gotten any trace logs yet, so I've asked in the other issue to collect some. That should help understand the ordering.

Thanks for contacting us.
We're moving this issue to the Next sprint planning milestone for future evaluation / consideration. We will evaluate the request when we are planning the work for the next milestone. To learn more about what to expect next and how this issue will be handled you can read more about our triage process here.

[aventus13]

Please see attached for the trace logs
vscode-debugadapter-0.json.gz

[connor4312]

That appears to be a separate issue, looks like the Blazor proxy is not running:

"Unable to launch browser: "Could not open ws://localhost:5001/_framework/debug/ws-proxy?browser=ws%3A%2F%2F127.0.0.1%3A50835%2Fdevtools%2Fbrowser%2F57772b19-838c-45c9-9a60-20ea02b21f62""

(thrown from new Websocket(...).on('error')

[aventus13]

Should I raise a separate issue for it then? Am I missing some setup? How do I run the Blazor proxy?

[captainsafia]

@aventus13 You're in our repo now. Can you share the version of Blazor that you were using when you encountered this issue?

Thanks,
Safia