The binary rewriter that currently strips S.P.CoreLib.dll turns out to have been removing some instances of serialization infrastructure on types it retained. That implies that we don't have test coverage for binary serializing these.

Investigate, and add coverage if necessary. If the type is internal to S.P.CoreLib.dll and is not serialized indirectly then possibly it isn't necessary. If the type is missing [Serializable] on it, it's also not necessary.

What I grepped for

[OnDeserialized]
[OnSerializing]
[OnSerialized]
serialization constructor or other function passed SerializationInfo

Types affected were in

• mscorlib/src/System/Globalization/SortKey.cs
• mscorlib/src/System/Security/Util/TokenBasedSet.cs
• mscorlib/src/System/Security/Util/URLString.cs
• mscorlib/src/System/Security/PermissionSet.cs (PermissionSet)
• mscorlib/src/System/Text/*Encoding.cs
• mscorlib/src/System/AppDomainUnloadedException.cs
• mscorlib/src/System/Collections/Comparer.cs
• mscorlib/src/System/Collections/Generic/Comparer.cs (several classes)
• mscorlib/src/System/Collections/Hashtable.cs (the internal hashtable)
• mscorlib/src/System/IO/DriveNotFoundException.cs
• mscorlib/src/System/InsufficientMemoryException.cs
• mscorlib/src/System/OperatingSystem.cs
• mscorlib/src/System/Reflection/ConstructorInfo.cs
• mscorlib/src/System/Runtime/CompilerServices/RuntimeWrappedException.cs
• mscorlib/src/System/Runtime/Serialization/FormatterServices.cs - SurrogateForCyclicalReference
• mscorlib/src/System/Runtime/Serialization/ISurrogateSelector.cs
• mscorlib/src/System/Text/DecoderNLS.cs

@stephentoub fyi.