Why am I getting this warning when building Orchard in VS2012: JetBrain Annotations conflict

Topics: Customizing Orchard, Troubleshooting
Feb 27, 2013 at 8:52 AM
There is a duplicated class between Orchard source and NHibernate ?
Do I use the good NHibernate ?
Detail file version

Warning 1 The type 'JetBrains.Annotations.AssertionMethodAttribute' in 'e:\Datwendo\Orchard4\src\Orchard\Validation\JetBrains.Annotations.cs' conflicts with the imported type 'JetBrains.Annotations.AssertionMethodAttribute' in 'e:\Datwendo\Orchard4\lib\nhibernate\NHibernate.dll'. Using the type defined in 'e:\Datwendo\Orchard4\src\Orchard\Validation\JetBrains.Annotations.cs'. E:\Datwendo\Orchard4\src\Orchard\Validation\Argument.cs 6 10 Orchard.Framework
Feb 27, 2013 at 2:16 PM
It looks like the AssertionConditionAttribute conflicts with a class with the same name in the same namespace in the NHibernate assembly.
Please file a bug.