[wasm] Read messages from binlog if process output is missing build finished message

[maraf]

Mitigates #106160

[maraf]

/azp run runtime

[azure-pipelines]

Pull request contains merge conflicts.

[maraf]

This trick with replacing text process output by messages from binlog works https://helixre107v0xdcypoyl9e7f.blob.core.windows.net/dotnet-runtime-refs-pull-107280-merge-d302933e6fae4921a6/Workloads-NoWebcil-ST-Wasm.Build.Tests.TestAppScenarios.SatelliteLoadingTests/1/console.e29afe23.log?helixlogtype=result

[dotnet-policy-service]

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[ilonatommy]

What are these failures? They do not look connected with the change but I cannot find an active issue. And there's a lot of them

Assert.Contains() Failure: Sub-string not found
      String:    "Property reassignment: $(MSBuildProjectEx"···
      Not found: "error : Stopping the build"
      Stack Trace:
        /_/src/mono/wasm/Wasm.Build.Tests/Blazor/WorkloadRequiredTests.cs(177,0): at Wasm.Build.Tests.Blazor.WorkloadRequiredTests.CheckWorkloadRequired(String config, String extraProperties, Boolean workloadNeeded, Boolean publish)
        /_/src/mono/wasm/Wasm.Build.Tests/Blazor/WorkloadRequiredTests.cs(62,0): at Wasm.Build.Tests.Blazor.WorkloadRequiredTests.WorkloadRequiredForPublish(String config, String extraProperties, Boolean workloadNeeded)
           at InvokeStub_WorkloadRequiredTests.WorkloadRequiredForPublish(Object, Span`1)
           at System.Reflection.MethodBaseInvoker.InvokeWithFewArgs(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

[maraf]

I think it's connected. Probably the build fails there with a different message than I'm expecting...

[ilonatommy]

Didn't you overwrite the output that is normally returned by this method? We are failing in

runtime/src/mono/wasm/Wasm.Build.Tests/Blazor/WorkloadRequiredTests.cs

Line 171 in 2c5b609

Assert.Contains("following workloads must be installed: wasm-tools", result.Output);

so it looks like it's looking for a line that should be there but is not. Can't we append to the existing output when we get res? And merge that res.Output with the previous values from line 174?

[maraf]

Normally it would mean that get the output doubled, which might be... weird. My goal (atm) is to override the output only when the process output is incomplete.

[ilonatommy]

Should be fine now