Whilst building a new TFS build agent VM using our standard scripts I hit a problem that SSDT projects would not build, but was fine on our existing agents. The error was
C:Program Files (x86)MSBuildMicrosoftVisualStudiov12.0SSDTMicrosoft.Data.Tools.Schema.SqlTasks.targets (513): The “SqlBuildTask” task failed unexpectedly.
System.MethodAccessException: Attempt by method ‘Microsoft.Data.Tools.Schema.Sql.Build.SqlTaskHost.OnCreateCustomSchemaData(System.String, System.Collections.Generic.Dictionary`2<System.String,System.String>)’ to access method ‘Microsoft.Data.Tools.Components.Diagnostics.SqlTracer.ShouldTrace(System.Diagnostics.TraceEventType)’ failed.
The problem was fixed by doing an update via the Visual Studio > Tools > Extensions and Updates. Once this was completed the build was fine.
Seems there may have been an issue with the Update 3 generation SSDT tools, so older and newer versions seem OK. Our existing agents had already been patched.