MsBuild StartsWith not Evaluating In Condition?

Question

In trying to get some code coverage tools set up and working on a new Xamarin.Forms project via VisualStudio on Mac, I am trying to use netfx.props as suggested in mac/linux `dotnet build` The reference assemblies for framework ".NETFramework.." were not found . (I would comment there directly for this question, but alas, I don't have enough reputation points.)

<?xml version="1.0" encoding="utf-8"?>
<!-- Copyright (c) Microsoft Corporation.  All Rights Reserved.  See License.txt in the project root for license information. -->
<Project ToolsVersion="4.0" DefaultTargets="Build" xmlns="http://schemas.microsoft.com/developer/msbuild/2003">
  <PropertyGroup>
    <!-- When compiling .NET SDK 2.0 projects targeting .NET 4.x on Mono using 'dotnet build' you -->
    <!-- have to teach MSBuild where the Mono copy of the reference asssemblies is -->
    <TargetIsMono Condition="($(TargetFramework.StartsWith('net4')) OR $(TargetFrameworkVersion.StartsWith('v4.'))) AND '$(OS)' == 'Unix'">true</TargetIsMono>

    <!-- Look in the standard install locations -->
    <BaseFrameworkPathOverrideForMono Condition="'$(BaseFrameworkPathOverrideForMono)' == '' AND '$(TargetIsMono)' == 'true' AND EXISTS('/Library/Frameworks/Mono.framework/Versions/Current/lib/mono')">/Library/Frameworks/Mono.framework/Versions/Current/lib/mono</BaseFrameworkPathOverrideForMono>
    <BaseFrameworkPathOverrideForMono Condition="'$(BaseFrameworkPathOverrideForMono)' == '' AND '$(TargetIsMono)' == 'true' AND EXISTS('/usr/lib/mono')">/usr/lib/mono</BaseFrameworkPathOverrideForMono>
    <BaseFrameworkPathOverrideForMono Condition="'$(BaseFrameworkPathOverrideForMono)' == '' AND '$(TargetIsMono)' == 'true' AND EXISTS('/usr/local/lib/mono')">/usr/local/lib/mono</BaseFrameworkPathOverrideForMono>

    <!-- If we found Mono reference assemblies, then use them -->
    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND ('$(TargetFramework)' == 'net45' OR '$(TargetFrameworkVersion)' == 'v4.5')">$(BaseFrameworkPathOverrideForMono)/4.5-api</FrameworkPathOverride>
    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND ('$(TargetFramework)' == 'net451' OR '$(TargetFrameworkVersion)' == 'v4.5.1')">$(BaseFrameworkPathOverrideForMono)/4.5.1-api</FrameworkPathOverride>
    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND ('$(TargetFramework)' == 'net452' OR '$(TargetFrameworkVersion)' == 'v4.5.2')">$(BaseFrameworkPathOverrideForMono)/4.5.2-api</FrameworkPathOverride>
    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND ('$(TargetFramework)' == 'net46' OR '$(TargetFrameworkVersion)' == 'v4.6')">$(BaseFrameworkPathOverrideForMono)/4.6-api</FrameworkPathOverride>
    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND ('$(TargetFramework)' == 'net461' OR '$(TargetFrameworkVersion)' == 'v4.6.1')">$(BaseFrameworkPathOverrideForMono)/4.6.1-api</FrameworkPathOverride>
    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND ('$(TargetFramework)' == 'net462' OR '$(TargetFrameworkVersion)' == 'v4.6.2')">$(BaseFrameworkPathOverrideForMono)/4.6.2-api</FrameworkPathOverride>
    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND ('$(TargetFramework)' == 'net47' OR '$(TargetFrameworkVersion)' == 'v4.7')">$(BaseFrameworkPathOverrideForMono)/4.7-api</FrameworkPathOverride>
    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND ('$(TargetFramework)' == 'net471' OR '$(TargetFrameworkVersion)' == 'v4.7.1')">$(BaseFrameworkPathOverrideForMono)/4.7.1-api</FrameworkPathOverride>
    <FrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != '' AND ('$(TargetFramework)' == 'net472' OR '$(TargetFrameworkVersion)' == 'v4.7.2')">$(BaseFrameworkPathOverrideForMono)/4.7.2-api</FrameworkPathOverride>
    <EnableFrameworkPathOverride Condition="'$(BaseFrameworkPathOverrideForMono)' != ''">true</EnableFrameworkPathOverride>

    <!-- Add the Facades directory.  Not sure how else to do this. Necessary at least for .NET 4.5 -->
    <AssemblySearchPaths Condition="'$(BaseFrameworkPathOverrideForMono)' != ''">$(FrameworkPathOverride)/Facades;$(AssemblySearchPaths)</AssemblySearchPaths>
  </PropertyGroup>

  <ItemGroup Condition="'$(TargetFramework)'== 'net472' OR '$(TargetFrameworkVersion)' == 'v4.7.2'">
    <Reference Include="netstandard" />
  </ItemGroup>
</Project>

The file is imported via the .csproj fine, but it still wasn't working, so I printed some debug messaging using:

    <Target Name="test">
        <Message Importance="High" Text="TargetFramework value is '$(TargetFramework)', starts with net4 is '$(TargetFramework.StartsWith('net4'))'" />
        <Message Importance="High" Text="TargetFrameworkVersion value is '$(TargetFrameworkVersion)', starts with v4 is '$(TargetFrameworkVersion.StartsWith('v4'))'" />
        <Message Importance="High" Text="OS value is '$(OS)'" />
        <Message Importance="High" Text="TargetIsMono value is '$(TargetIsMono)'" />
        <Message Importance="High" Text="BaseFrameworkPathOverrideForMono value is '$(BaseFrameworkPathOverrideForMono)'" />
        <Message Importance="High" Text="FrameworkPathOverride value is '$(FrameworkPathOverride)'" />
        <Message Importance="High" Text="EnableFrameworkPathOverride value is '$(EnableFrameworkPathOverride)'" />
    </Target>

and saw that:

  TargetFramework value is '', starts with net4 is 'False'
  TargetFrameworkVersion value is 'v4.7', starts with v4 is 'True'
  OS value is 'Unix'
  TargetIsMono value is ''
  BaseFrameworkPathOverrideForMono value is ''
  FrameworkPathOverride value is '/Library/Frameworks/Mono.framework/Versions/6.6.0/lib/mono/4.7-api'
  EnableFrameworkPathOverride value is ''

TargetIsMono remains empty even though it should have been set to 'true' because of the TargetFrameworkVersion.StartsWith and OS . After playing around with the TargetIsMono Condition , the issue seems to be that even though the StartsWith s have correct boolean values according to the print messages, they are not actually evaluating properly in the Condition .

Ie,

    <TargetIsMono Condition="$(TargetFrameworkVersion.StartsWith('v4.'))>true</TargetIsMono>

does not set TargetIsMono to 'true' even though it should.

Does anyone have any ideas? I am new to MsBuild, Xamarin.Forms, and VisualStudio. Any help would be appreciated!

Answer 1

I switched target framework version to 4.8 then back to 4.7, and this resolved itself. ¯\\_(ツ)_/¯