xsd.exe generates duplicate attributes when run on OFX2 schema

Question

Using the command line:

"xsd.exe" "OFX 2.1.1 schema/OFX2_Protocol.xsd" /c /namespace:OFX /nologo"

The resulting C# source file fails to build with these errors:

D:\blah\OFX2_Protocol.cs(19,6): error CS0579: Duplicate 'System.CodeDom.Compiler.GeneratedCodeAttribute' attribute
D:\blah\OFX2_Protocol.cs(20,6): error CS0579: Duplicate 'System.SerializableAttribute' attribute
D:\blah\OFX2_Protocol.cs(21,6): error CS0579: Duplicate 'System.Diagnostics.DebuggerStepThroughAttribute' attribute
D:\blah\OFX2_Protocol.cs(22,6): error CS0579: Duplicate 'System.ComponentModel.DesignerCategoryAttribute' attribute
D:\blah\OFX2_Protocol.cs(23,6): error CS0579: Duplicate 'System.Xml.Serialization.XmlTypeAttribute' attribute
D:\blah\OFX2_Protocol.cs(24,6): error CS0579: Duplicate 'System.Xml.Serialization.XmlRootAttribute' attribute

A similar XSD schema, which I copied from the OFX2 schema then trimmed down to the useful bits that I wanted, generates a C# file which builds just fine, yet has all the same attributes as the full schema's C# representation.

Any idea why? Is the OFX schema broken? Is xsd.exe broken? Is C# broken? Am I broken?

Answer 1

I don't like being labelled as having a 95% accept rate just because I've not accepted an answer for this question, so I'm answering it with "xsd.exe is broken", which as far as I can tell is the closest to the truth (given all the other problems it has).