fails

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    <Platform Condition=" '$(Platform)' == '' ">AnyCPU</Platform>
    <ProductVersion>10.0.0</ProductVersion>
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    <RootNamespace>Cirrious.CrossCore.Touch</RootNamespace>
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    <AssemblyName>Cirrious.CrossCore.Touch</AssemblyName>
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    <DebugType>full</DebugType>
    <Optimize>False</Optimize>
    <OutputPath>..\..\bin\Debug\Mvx\Touch\</OutputPath>
    <DefineConstants>DEBUG;</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <ConsolePause>False</ConsolePause>
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    <DebugType>none</DebugType>
    <Optimize>True</Optimize>
    <OutputPath>..\..\bin\Release\Mvx\Touch\</OutputPath>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <ConsolePause>False</ConsolePause>
  </PropertyGroup>
  <ItemGroup>
    <Reference Include="System" />
    <Reference Include="System.Core" />
    <Reference Include="Xamarin.iOS" />
  </ItemGroup>
  <ItemGroup />
  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.MonoTouch.CSharp.targets" />
  <ItemGroup>
    <Compile Include="Platform\IMvxTouchSystem.cs" />
    <Compile Include="Platform\MvxIosMajorVersionChecker.cs" />
    <Compile Include="Platform\MvxTouchSystem.cs" />
    <Compile Include="Platform\MvxTouchVersion.cs" />
    <Compile Include="Views\IMvxTouchModalHost.cs" />
    <Compile Include="MvxTouchColorExtensionMethods.cs" />
    <Compile Include="MvxTouchDateTimeExtensionMethods.cs" />
    <Compile Include="MvxTouchUIViewControllerExtensions.cs" />
    <Compile Include="Platform\MvxTouchTask.cs" />
    <Compile Include="Views\MvxBaseViewControllerAdapter.cs" />
    <Compile Include="Views\MvxEventSourceCollectionViewController.cs" />
    <Compile Include="Views\MvxEventSourceTabBarController.cs" />
    <Compile Include="Views\MvxEventSourceTableViewController.cs" />
    <Compile Include="Views\MvxEventSourceViewController.cs" />
    <Compile Include="Views\IMvxEventSourceViewController.cs" />
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  <ItemGroup>
    <ProjectReference Include="..\Cirrious.CrossCore\Cirrious.CrossCore.csproj">
      <Project>{CFF6F25A-3C3B-44EE-A54C-2ED4AAFF3ADB}</Project>
      <Name>Cirrious.CrossCore</Name>
    </ProjectReference>
  </ItemGroup>
  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
</Project>

works

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    <Configuration Condition=" '$(Configuration)' == '' ">Debug</Configuration>
    <Platform Condition=" '$(Platform)' == '' ">iPhoneSimulator</Platform>
    <ProductVersion>8.0.30703</ProductVersion>
    <SchemaVersion>2.0</SchemaVersion>
    <ProjectGuid>{B7B1B384-7260-4809-B6BA-BDFB02FFC0A2}</ProjectGuid>
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    <OutputType>Library</OutputType>
    <RootNamespace>deletethis</RootNamespace>
    <IPhoneResourcePrefix>Resources</IPhoneResourcePrefix>
    <AssemblyName>deletethis</AssemblyName>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Debug|AnyCPU' ">
    <DebugSymbols>true</DebugSymbols>
    <DebugType>full</DebugType>
    <Optimize>false</Optimize>
    <OutputPath>bin\iPhone\Debug</OutputPath>
    <DefineConstants>DEBUG</DefineConstants>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <ConsolePause>false</ConsolePause>
    <MtouchDebug>true</MtouchDebug>
    <CodesignKey>iPhone Developer</CodesignKey>
  </PropertyGroup>
  <PropertyGroup Condition=" '$(Configuration)|$(Platform)' == 'Release|AnyCPU' ">
    <DebugType>none</DebugType>
    <Optimize>true</Optimize>
    <OutputPath>bin\iPhone\Release</OutputPath>
    <ErrorReport>prompt</ErrorReport>
    <WarningLevel>4</WarningLevel>
    <ConsolePause>false</ConsolePause>
    <CodesignKey>iPhone Developer</CodesignKey>
  </PropertyGroup>
  <ItemGroup>
    <Compile Include="Class1.cs" />
    <Compile Include="Properties\AssemblyInfo.cs" />
  </ItemGroup>
  <ItemGroup>
  </ItemGroup>
  <ItemGroup>
    <Reference Include="System" />
    <Reference Include="System.Xml" />
    <Reference Include="System.Core" />
    <Reference Include="Xamarin.iOS" />
  </ItemGroup>
  <Import Project="$(MSBuildExtensionsPath)\Xamarin\iOS\Xamarin.iOS.CSharp.targets" />
</Project>