since 1.25 xUnit fails build:
UnitTest# Hermes version 2.3.9.24513 (dynamic) from 10/27/2011 12:37:35 PM
NUnit version 2.5.3.0
Copyright (C) 2002-2009 Charlie Poole.
Copyright (C) 2002-2004 James W. Newkirk, Michael C. Two, Alexei A. Vorontsov.
Copyright (C) 2000-2002 Philip Craig.
All Rights Reserved.

Runtime Environment -
OS Version: Microsoft Windows NT 5.2.3790 Service Pack 2
CLR Version: 2.0.50727.3623 ( Net 2.0.50727.3623 )

ProcessModel: Default DomainUsage: Multiple
Execution Runtime: net-2.0.50727.3623
..................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................................
Tests run: 754, Errors: 0, Failures: 0, Inconclusive: 0, Time: 8.187238 seconds
Not run: 0, Invalid: 0, Ignored: 0, Skipped: 0

[WARNINGS] Parsing warnings in console log with parsers [MSBuild]
[WARNINGS] MSBuild : Found 0 warnings.
[xUnit] [INFO] - Starting to record.
[xUnit] [INFO] - Processing NUnit-Version N/A (default)
[xUnit] [WARNING] - Can't create the path C:\Hudson\workspace\HermesSharpSvn2008Release\generatedJUnitFiles. Maybe the directory already exists.
[xUnit] [ERROR] - The plugin hasn't been performed correctly: There are some problems during the conversion into JUnit reports: null
Build step 'Publish testing tools result report' changed build result to FAILURE
Build step 'Publish testing tools result report' marked build as failure

I have to downgrade xUnit 1.26 to 1.24 to fix build:
[xUnit] [INFO] - Starting to record.
[xUnit] [INFO] - Processing NUnit-Version N/A (default)
[xUnit] [WARNING] - Can't create the path C:\Hudson\workspace\HermesSharpSvn2008Release\generatedJUnitFiles. Maybe the directory already exists.
[xUnit] [INFO] - [NUnit-Version N/A (default)] - 1 test report file(s) were found with the pattern '**/hermes-test.xml' relative to 'C:\Hudson\workspace\HermesSharpSvn2008Release' for the testing framework 'NUnit-Version N/A (default)'.
[xUnit] [INFO] - Stopping recording.

Not sure where to get additional information about error