xsd.exe crashes with "Object reference not set to an instance of an object" error

I have also asked this at StackOverflow, but so far, nobody seems to know an answer. In a related thread on this MSDN forum, the question was never updated with an answer either, though the user seems to have been helped.

I am trying to use xsd.exe to generate C# classes of a valid XSD file. The file itself is part of the XSLT 3.0 Test Suite andcan be found at its public DVCS location here. The full error and version information is as follows:

Microsoft (R) Xml Schemas/DataTypes support utility
[Microsoft (R) .NET Framework, Version 4.0.30319.17929]
Copyright (C) Microsoft Corporation. All rights reserved.
Error: Error generating classes for schema 'xml_catalog-schema'.
  - Object reference not set to an instance of an object.

The commandline I used was the following, but the error is the same with or without xml.xsd.

xsd xml.xsd catalog-schema.xsd /classes

Any idea how to troubleshoot this issue and/or whether the source of xsd.exe is available somewhere, because to me, this clearly seems to be a bug in the SDK tool.