Steps to reproduce

dotnet create xunit
dotnet test --verbosity diagnostic

You can find messy messages by text Test Execution Command Line Tool Version

Expected behavior

Each message should be on the own line and should not be mixed

Actual behavior

Messages are mixed, sometimes happens that one message is interrupted by another in the middle.

See the attached

Environment data

dotnet --info
.NET Command Line Tools (2.1.201)

Product Information:
Version: 2.1.201
Commit SHA-1 hash: 7932dc6

Runtime Environment:
OS Name: Windows
OS Version: 10.0.17134
OS Platform: Windows
RID: win10-x64
Base Path: C:\Program Files\dotnet\sdk\2.1.201\

Microsoft .NET Core Shared Framework Host

Version : 2.0.7
Build : 2d61d0b043915bc948ebf98836fefe9ba942be11