Building WP8.0 assembly from code - msbuild

Question

I'm trying to build a WP 8.0 project in code. I'm using the Project class and the Build method, source code is available here.
The code worked on Windows 8 using VS 2012, but while I upgraded to Windows 8.1 and VS2013, it stopped working. I know that Microsoft changed and removed the Build framework from .NET in VS, but I am still not sure why it happens and how can I fix it.
The error:
C:\Program Files
(x86)\MSBuild\Microsoft\WindowsPhone\v8.0\Microsoft.WindowsPhone.Common.targets(75,5):
error MSB4127: The "GetSilverlightFrameworkPath" task could not be
instantiated from the assembly "C:\Program Files
(x86)\MSBuild\Microsoft\WindowsPhone\v8.0\Microsoft.Silverlight.WindowsPhone.Build.Tasks.dll".
Please verify the task assembly has been built using the same version
of the Microsoft.Build.Framework assembly as the one installed on your
computer and that your host application is not missing a binding
redirect for Microsoft.Build.Framework. Unable to cast object of type
'Microsoft.Silverlight.Build.Tasks.GetSilverlightFrameworkPath' to
type 'Microsoft.Build.Framework.ITask'.C:\Program Files
(x86)\MSBuild\Microsoft\WindowsPhone\v8.0\Microsoft.WindowsPhone.Common.targets(75,5):
error MSB4060: The "GetSilverlightFrameworkPath" task has been
declared or used incorrectly, or failed during construction. Check the
spelling of the task name and the assembly name.
UPDATE:
By the way the WP 8.0 is compiled using VS2013, the problem occurs when trying to build it from code.

Answer 1

You are getting this error because Microsoft.Silverlight.WindowsPhone.Build.Tasks.dll is the assembly which holds GetSilverlightFrameworkPath, e.g. in the Silverlight 4 and 5 SDK:
// Decompiled with JetBrains decompiler
// Type: Microsoft.Silverlight.Build.Tasks.GetSilverlightFrameworkPath
// Assembly: Microsoft.Silverlight.Build.Tasks, Version=9.3.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
// MVID: 2E9B62C4-1C0C-4AAD-8CBE-F7E074602879
// Assembly location: C:\Program Files (x86)\MSBuild\Microsoft\Silverlight\v5.0
//omitted for brevity
namespace Microsoft.Silverlight.Build.Tasks
{
public sealed class GetSilverlightFrameworkPath : Task
{
private const string SDKAssemblyFoldersExRegKey = "v5.0\\AssemblyFoldersEx";
public const string SDKLibrariesRegKey = "v5.0\\AssemblyFoldersEx\\Silverlight SDK Client Libraries";
public const string SDKRuntimeInstallPathRegKey = "SOFTWARE\\Microsoft\\Microsoft SDKs\\Silverlight\\v5.0\\ReferenceAssemblies";
public string RegistryBase { get; set; }
public string SilverlightPath { get; set; }
public string[] SilverlightSDKPaths { get; set; }
public string SilverlightRuntimeVersion { get; set; }
public override bool Execute()
{
//omitted for brevity
}
private string GetSilverlightPath()
{
//omitted for brevity
}
private string GetSDKRuntimeVersion()
{
//omitted for brevity
}
private string[] GetAllSilverlightSDKPaths()
{
//omitted for brevity
}
}
}
However, its implementation in WP v8.0 seems quite different indeed:
// Decompiled with JetBrains decompiler
// Type: Microsoft.Silverlight.Build.Tasks.GetSilverlightFrameworkPath
// Assembly: Microsoft.Silverlight.WindowsPhone.Build.Tasks, Version=9.3.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a
// MVID: 899BFFD0-786C-472A-8935-576EED0F4F90
// Assembly location: C:\Program Files (x86)\MSBuild\Microsoft\WindowsPhone\v8.0\Microsoft.Silverlight.WindowsPhone.Build.Tasks.dll
//omitted for brevity
namespace Microsoft.Silverlight.Build.Tasks
{
public sealed class GetSilverlightFrameworkPath : Task
{
public string RegistryBase { get; set; }
public string RuntimePathRegistryKey { get; set; }
public string RuntimeVersionRegistryKey { get; set; }
public string AdditionalRegistryBasePaths { get; set; }
public string SilverlightPath { get; set; }
public string[] SilverlightSDKPaths { get; set; }
public string SilverlightRuntimeVersion { get; set; }
public override bool Execute()
{
// omitted for brevity
}
private string GetSilverlightPath()
{
// omitted for brevity
}
private string GetSDKRuntimeVersion()
{
// omitted for brevity
}
internal string[] GetAllSilverlightSDKPaths()
{
// omitted for brevity
}
}
Therefore, it is quite natural that things do not work.
What you need to do is check that you are referencing the same SDK versions in all your projects.
The Task you are trying to instantiate during the build is in SL SDK 5 whereas currently for some reason the build process is trying to use the WP8.0 SDK.
Moreover, the code you referenced is part of a csproj that references Toolset 12.0:
<?xml version="1.0" encoding="utf-8"?>
<Project ToolsVersion="12.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
Are you certain that is desired?
This info might also be relevant to you.
If you provide more info on your actual project, it can probably be easily fixed. Right now, it is a bit difficult to judge how everything is set up.