DoubleWrites message is recorded when using `--output` parameter on dotnet command

[filzrev]

When benchmark project and dependent projects supports multiple TFMs.
DoubleWrites messages are recorded unexpectedly.

It's occurred when using --output parameter on dotnet command without --no-dependencies.

How to reproduce problem

1. Run samples\BenchmarkDotNet.Samples benchmark with following parameter.

   dotnet run -c Release -f net10.0 --no-launch-profile -- --filter IntroBasic --keepFiles --generateBinLog

2. Open generated binlog file that is generated in bin\Release\net8.0\BenchmarkDotNet.Samples-DefaultJob-1
3. Confirm DoubleWrites logs exists.

   

Additionally, following warning is also recorded.
(It should not be occurred. Because there is no System.Threading.Channels dependency on net8.0 tfm build)

warning MSB3277:
Found conflicts between different versions of "System.Threading.Channels" that could not be resolved.

Background

Currently, BenchmarkDotNet using --output parameter when buildinding Autogenerated project.
Though, it's not works as expected when dependent projects tfm is resolved to multiple TFMs.

Example:

• BenchmarkDotNet.csproj (net8.0) -> BenchmarkDotNet.dll (net8.0)
• BenchmarkDotNet.Diagnostics.Windows (netstandard2.0) ->BenchmarkDotNet.csproj (netstandard2.0) -> BenchmarkDotNet.dll (netstandard2.0)

Double Writes issue is occurred because both project output are copied to single directory (Specified with --output)

It also might affects benchmark results. (It's not defined which version of DLL is used)

Expected solution

• Use .NET 8 SDK as minimum requirements to use ArtifactsPath
• Add .NET SDK validator to check dotnet --version return .NET 8 SDK or greater.
• Build Original benchmark projects with ArtifactsPath option (Don't use --output)
• Modify DllGatherer related logics
• Build Autogenerated project with --no-restore --no-dependencies and ArtifactsPath and --output option.

[filzrev]

Following part of changes are handled by #3194

• Use .NET 8 SDK as minimum requirements to use ArtifactsPath
• Add .NET SDK validator to check dotnet --version return .NET 8 SDK or greater.

When implementing other changes, it must pass following tests.

1. Verify samples\BenchmarkDotNet.Samples's IntroBasic benchmarks succeeded with Release configuration.
2. Verify samples\BenchmarkDotNet.Samples's IntroBasic benchmarks succeeded with Debug configuration (BuildPartition.IsCustomBuildConfiguration=true)
3. IntegrationTests passed on Debug and Release configurations
4. Verify same file contents are outputted on bin directory (with --keepFiles)
   4.1. runtime assets from referenced package.
   4.2. resources assets from referenced package.
   4.3. native assets from Gee.External.Capstone package.
   4.4. Other assets that are copied from NuGet package with custom NuGet targets.

[hiSandog]

A toolchain regression test could invoke dotnet once with --output and once without it while capturing both the generated command line and diagnostic stream. The assertion should distinguish a genuinely duplicated write from the SDK's expected warning so the message is neither falsely recorded nor globally suppressed. Including the newer --artifacts-path alternative could clarify whether only --output requires special handling.

[timcassell]

• Modify DllGatherer related logics

Any progress on that? If it's not too complicated, it's better to get that into 0.16 I think.