a·gen·tic a·gil·i·ty

TFS Error: MSB4018 The "BuildShadowTask" task failed unexpectedly

TL;DR; Explains the MSB4018 “BuildShadowTask” error in TFS when using Accessors in unit test projects, its cause, and how removing .accessor files resolves build issues.

Published on
2 minute read
Image
https://nkdagility.com/resources/xi_wQ8zFW_U
Subscribe

There seams to be a problem in MSBuild when you add an “Accessor” as part of a Unit Test project.

 1C:Program FilesMSBuildMicrosoftVisualStudiov9.0TeamTestMicrosoft.TeamTest.targets(14,5): error MSB4018: The "BuildShadowTask" task failed unexpectedly.
 2System.IO.FileLoadException: API restriction: The assembly 'file:///C:WINDOWSMicrosoft.NETFrameworkv2.0.50727System.Web.dll' has already loaded from a different location. It cannot be loaded from a new location within the same appdomain.
 3   at System.Reflection.Assembly._nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)
 4   at System.Reflection.Assembly.nLoad(AssemblyName fileName, String codeBase, Evidence assemblySecurity, Assembly locationHint, StackCrawlMark& stackMark, Boolean throwOnFileNotFound, Boolean forIntrospection)
 5   at System.Reflection.Assembly.InternalLoad(AssemblyName assemblyRef, Evidence assemblySecurity, StackCrawlMark& stackMark, Boolean forIntrospection)
 6   at System.Reflection.Assembly.InternalLoadFrom(String assemblyFile, Evidence securityEvidence, Byte[] hashValue, AssemblyHashAlgorithm hashAlgorithm, Boolean forIntrospection, StackCrawlMark& stackMark)
 7   at System.Reflection.Assembly.ReflectionOnlyLoadFrom(String assemblyFile)
 8   at Microsoft.VisualStudio.TestTools.UnitTesting.Publicize.WebBinder.LoadData()
 9   at Microsoft.VisualStudio.TestTools.UnitTesting.Publicize.WebBinder.Init()
10   at Microsoft.VisualStudio.TestTools.UnitTesting.Publicize.Shadower..ctor()
11   at Microsoft.VisualStudio.TestTools.BuildShadowReferences.BuildShadowTask.Execute()
12   at Microsoft.Build.BuildEngine.TaskEngine.ExecuteInstantiatedTask(EngineProxy engineProxy, ItemBucket bucket, TaskExecutionMode howToExecuteTask, ITask task, Boolean& taskResult)

An Accessor allows your test project to access code that would normally be “Private” or “Friend” from outside the Assembly that it resides in.

TFS Error: MSB4018 The "BuildShadowTask" task failed unexpectedly

It creates a little file with the “.accessor” extension that is the same name as your DLL, and contains the name of the DLL.

TFS Error: MSB4018 The "BuildShadowTask" task failed unexpectedly

If you remove this file then your remote MSBuild server will then build you solution successfully again including running your Unit Tests.

Reference:

Re: BuildShadowTask Failed unexpectedly - Accessor Problem (Upconvert VS 2005 to 2008) – URGENT

BuildShadowTask Failed unexpectedly - Accessor Problem (Upconvert VS 2005 to 2008) – URGENT

Technorati Tags: ALM   TFBS   TFS 2008   VS 2005

Smart Classifications

Each classification [Concepts, Categories, & Tags] was assigned using AI-powered semantic analysis and scored across relevance, depth, and alignment. Final decisions? Still human. Always traceable. Hover to see how it applies.

Subscribe

Connect with Martin Hinshelwood

If you've made it this far, it's worth connecting with our principal consultant and coach, Martin Hinshelwood, for a 30-minute 'ask me anything' call.

Our Happy Clients​

We partner with businesses across diverse industries, including finance, insurance, healthcare, pharmaceuticals, technology, engineering, transportation, hospitality, entertainment, legal, government, and military sectors.​

Akaditi Logo

Akaditi

Bistech Logo

Bistech

Emerson Process Management Logo

Emerson Process Management

Workday Logo

Workday

NIT A/S

Hubtel Ghana Logo

Hubtel Ghana

Freadom Logo

Freadom

Higher Education Statistics Agency Logo

Higher Education Statistics Agency

ProgramUtvikling Logo

ProgramUtvikling

Sage Logo

Sage

Teleplan Logo

Teleplan

Kongsberg Maritime Logo

Kongsberg Maritime

Qualco Logo

Qualco

Schlumberger Logo

Schlumberger

MacDonald Humfrey (Automation) Ltd. Logo

MacDonald Humfrey (Automation) Ltd.

Slicedbread Logo

Slicedbread

Microsoft Logo

Microsoft

Healthgrades Logo

Healthgrades

New Hampshire Supreme Court Logo

New Hampshire Supreme Court

Washington Department of Transport Logo

Washington Department of Transport

Ghana Police Service Logo

Ghana Police Service

Department of Work and Pensions (UK) Logo

Department of Work and Pensions (UK)

Washington Department of Enterprise Services Logo

Washington Department of Enterprise Services

Royal Air Force Logo

Royal Air Force

Kongsberg Maritime Logo

Kongsberg Maritime

MacDonald Humfrey (Automation) Ltd. Logo

MacDonald Humfrey (Automation) Ltd.

Freadom Logo

Freadom

Xceptor - Process and Data Automation Logo

Xceptor - Process and Data Automation

Graham & Brown Logo

Graham & Brown

Qualco Logo

Qualco