How to suppress the annoying warning message, "The dependency 'Microsoft.BizTalk.Tracing' could not be found."

I got the following warning messages when building a BizTalk project.

------ Build started: Project: BizTalkApp, Configuration: Development .NET ------
Updating references...
The dependency 'Microsoft.BizTalk.Tracing' could not be found.
The dependency 'Microsoft.BizTalk.Bam.EventObservation' could not be found.
The dependency 'Microsoft.BizTalk.Streaming' could not be found.
The dependency 'Microsoft.BizTalk.XPathReader' could not be found.
Performing main compilation...

I think these warning messages are no harm at runtime. But, they may annoy. The BizTalk project had a reference to a pipeline component project using some BizTalk related components such as Microsoft.BizTalk.Pipeline.dll.
To suppress these warning messages, you can select "False" for the "Copy Local" property of the referenced pipeline project in the BizTalk project. After then, they will be gone.