Breaking Changes in PostSharp 6.5

PostSharp 6.5 contains the following breaking changes:

Changes causing build errors

• In MulticastAttribute, setting AllowMultiple to false did not raise an error when two attributes are directly added to the same declaration and now will.

• It used to be possible to add a reference to an internal custom attribute declared in a different assembly using CopyCustomAttributesAttribute. This will now cause a build error. PostSharp used to add references to internal custom attributes generated by the C# compiler to represent reference type nullability. PostSharp will now instead use the custom attributes in the current assembly. If the current assembly is null-oblivious, reference type nullability information will not be copied.

Changes causing a silent change in behavior

• The order of execution of the RuntimeInitialize method did not respect aspect dependencies and now will. You may experience a change of execution order, but it should be for the better.

Deprecated platforms and features

• Visual Studio 2017 RTM (15.0) is no longer supported. Visual Studio 2017 Update 1 (15.9) is supported instead.