Add treat warnings as error option for ccrewriter about codecontracts

[hubuk]

I think you mean ccchecker not ccrewriter.
Cccheck is a static analyzer which report contract violations during build.
In that case you may select "Fail build on warnings" option in project properties on Code Contracts property page. If this option is grayed-out you need to disable "Check in background" option.
Is this the option you are looking for?

[reitzmichnicht]

No ccrewriter is correct. ccrewriter issues warnings for example when contracts are added to interface methods. I want to treat this as error.

[hubuk]

@reitzmichnicht This functionality seems to be already implemented. Try specifying /failOnWarnings in Extra Runtime Checker Options for the project.