[NETSDKE2E]With .NET 10 RC2, hostfxr probing messages are displayed in terminal output when running some dotnet command.

[NicoleWang001]

REGRESSION INFO
Worked well on .NET 10 RC1

INSTALL STEP

1. Install .NET 10 RC2 SDK

REPRO STEPS

1. Run command like dotnet new/build/restore/run/test and etc.

ACTUAL

1. dotnet command worked succeed but some redundant messages are displayed

EXPECTED:

1. dotnet command worked succeed with proper output message redundant messages are displayed

Dotnet --info
.NET SDK:
Version: 10.0.100-rc.2.25453.105
Commit: d7ddf64d2a
Workload version: 10.0.100-manifests.f0be4611
MSBuild version: 17.15.0-preview-25453-105+d7ddf64d2

Runtime Environment:
OS Name: Windows
OS Version: 10.0.26100
OS Platform: Windows
RID: win-x64
Base Path: C:\Program Files\dotnet\sdk\10.0.100-rc.2.25453.105\

.NET workloads installed:
There are no installed workloads to display.
Configured to use workload sets when installing new manifests.
No workload sets are installed. Run "dotnet workload restore" to install a workload set.

Host:
Version: 10.0.0-rc.2.25453.105
Architecture: x64
Commit: d7ddf64d2a

.NET SDKs installed:
10.0.100-rc.2.25453.105 [C:\Program Files\dotnet\sdk]

.NET runtimes installed:
Microsoft.AspNetCore.App 10.0.0-rc.2.25453.105 [C:\Program Files\dotnet\shared\Microsoft.AspNetCore.App]
Microsoft.NETCore.App 10.0.0-rc.2.25453.105 [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
Microsoft.WindowsDesktop.App 10.0.0-rc.2.25453.105 [C:\Program Files\dotnet\shared\Microsoft.WindowsDesktop.App]

Other architectures found:
None

Environment variables:
Not set

global.json file:
Not found

Learn more:
https://aka.ms/dotnet/info

Download .NET:
https://aka.ms/dotnet/download

[jinzhao1127]

When dotnet watch there are some error info

[baronfel]

hypothesis: the hostfxr global.json detection that was added in #50440 is polluting the terminal.

@elinor-fung would the hostfxr call ever write to stdout/stderr?

[baronfel]

This is impacting the Aspire CLI experience pretty dramatically.

[jtschuster]

would the hostfxr call ever write to stdout/stderr?

It looks like it does. We should be able to add a new API or flag to avoid writing to stdout/stderr.

[baronfel]

FWIW if this is especially risky we can always revert the PR and just not have the telemetry.