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.​

ProgramUtvikling Logo

ProgramUtvikling

Flowmaster (a Mentor Graphics Company) Logo

Flowmaster (a Mentor Graphics Company)

Kongsberg Maritime Logo

Kongsberg Maritime

Freadom Logo

Freadom

Milliman Logo

Milliman

Alignment Healthcare Logo

Alignment Healthcare

NIT A/S

Microsoft Logo

Microsoft

Genus Breeding Ltd Logo

Genus Breeding Ltd

CR2

SuperControl Logo

SuperControl

Emerson Process Management Logo

Emerson Process Management

Illumina Logo

Illumina

Slaughter and May Logo

Slaughter and May

Schlumberger Logo

Schlumberger

Brandes Investment Partners L.P. Logo

Brandes Investment Partners L.P.

Teleplan Logo

Teleplan

Cognizant Microsoft Business Group (MBG) Logo

Cognizant Microsoft Business Group (MBG)

Nottingham County Council Logo

Nottingham County Council

Department of Work and Pensions (UK) Logo

Department of Work and Pensions (UK)

Royal Air Force Logo

Royal Air Force

Washington Department of Enterprise Services Logo

Washington Department of Enterprise Services

New Hampshire Supreme Court Logo

New Hampshire Supreme Court

Ghana Police Service Logo

Ghana Police Service

Akaditi Logo

Akaditi

Cognizant Microsoft Business Group (MBG) Logo

Cognizant Microsoft Business Group (MBG)

SuperControl Logo

SuperControl

Xceptor - Process and Data Automation Logo

Xceptor - Process and Data Automation

Lean SA Logo

Lean SA

New Signature Logo

New Signature