testhost.dll is double written

[Youssef1313]

Description

See https://github.com/KirillOsenkov/MSBuildStructuredLog/wiki/Double%20write%20detection and https://www.meziantou.net/detecting-double-writes-in-msbuild-using-the-binlog.htm for info about double writes.

In a binlog from a private repo, I'm seeing testhost is double written.

Steps to reproduce

I didn't try to produce a minimal repro, but basically, the package props (https://github.com/microsoft/vstest/blob/39c7dd12c7ec24d0552513e84d95476f2077ca33/src/package/Microsoft.TestPlatform.TestHost/Microsoft.TestPlatform.TestHost.props) is marking testhost.dll in build/netcoreapp3.1/x64 directory as <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>. However, MSBuild also adds the testhost.dll from lib directory to ReferenceCopyLocalPaths.

Expected behavior

No double writes. It's a bit discouraged.

Actual behavior

Double writes.

Diagnostic logs

Environment

[nohwnd]

@drognanar I think you were investigating similar issue in the past, do you remember if it was resolved?