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We use NoStdLib in our Xamarin.iOS projects, and then manually reference mscorlib.dll. In 15.2, this no longer seems to work due to errors about referencing mscorlib.dll multiple times.
I removed NoStdLib from the project files, and removed the reference to mscorlib, but that results in the following warnings:
C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Xamarin\iOS\Xamarin.iOS.Common.targets(747, 3): Tool exited with code: 134. Output: warning MT0109: The assembly 'mscorlib.dll' was loaded from a different path than the provided path (provided path: /Users/xxx/Library/Caches/Xamarin/mtbs/builds/xxx/eb778e30a80662a3fd05d0855a9574ed/bin/Ad-Hoc-Test/mscorlib.dll, actual path: /Library/Frameworks/Xamarin.iOS.framework/Versions/10.10.0.33/lib/mono/Xamarin.iOS/mscorlib.dll).
Microsoft Visual Studio Professional 2017
Version 15.2 (26430.6) Release
Microsoft .NET Framework
Installed Version: Professional
Visual Basic 2017 00369-60000-00001-AA196
Microsoft Visual Basic 2017
Visual C# 2017 00369-60000-00001-AA196
Microsoft Visual C# 2017
Visual C++ 2017 00369-60000-00001-AA196
Microsoft Visual C++ 2017
Visual F# 4.1 00369-60000-00001-AA196
Microsoft Visual F# 4.1
Application Insights Tools for Visual Studio Package 8.6.00404.2
Application Insights Tools for Visual Studio
ASP.NET and Web Tools 2017 15.0.30503.0
ASP.NET and Web Tools 2017
ASP.NET Web Frameworks and Tools 2017 5.2.50303.0
For additional information, visit https://www.asp.net/
Azure App Service Tools v3.0.0 15.0.30209.0
Azure App Service Tools v3.0.0
Azure Data Lake Node 1.0
This package contains the Data Lake integration nodes for Server Explorer.
Azure Data Lake Tools for Visual Studio 2.2.5000.0
Microsoft Azure Data Lake Tools for Visual Studio
Common Azure Tools 1.9
Provides common services for use by Azure Mobile Services and Microsoft Azure Tools.
Fabric Diagnostic Events
JetBrains ReSharper Ultimate 2017.1.2 Build 108.0.20170428.75743
JetBrains ReSharper Ultimate package for Microsoft Visual Studio. For more information about ReSharper Ultimate, visit http://www.jetbrains.com/resharper. Copyright © 2017 JetBrains, Inc.
KofePackagePackage Extension 1.0
KofePackagePackage Visual Studio Extension Detailed Info
Merq 1.1.17-rc (cba4571)
Command Bus, Event Stream and Async Manager for Visual Studio extensions.
Microsoft Azure Hive Query Language Service 2.2.5000.0
Language service for Hive query
Microsoft Azure Tools 2.9
Microsoft Azure Tools for Microsoft Visual Studio 2017 - v2.9.50131.1
Microsoft MI-Based Debugger 1.0
Provides support for connecting Visual Studio to MI compatible debuggers
Microsoft Visual Studio VC Package 1.0
Microsoft Visual Studio VC Package
Mono Debugging for Visual Studio Mono.Debugging.VisualStudio
Support for debugging Mono processes with Visual Studio.
Node.js Tools 1.3.50417.1
Adds support for developing and debugging Node.js apps in Visual Studio
NuGet Package Manager 4.2.0
NuGet Package Manager in Visual Studio. For more information about NuGet, visit http://docs.nuget.org/.
PostSharp Tools for Visual Studio 18.104.22.168
PostSharp is the #1 pattern-aware extension to C# and VB.
SQL Server Data Tools 15.1.61702.140
Microsoft SQL Server Data Tools
Hosting json editor into a tool window
TypeScript tools for Visual Studio
Visual Studio Tools for Universal Windows Apps 15.0.26430.06
The Visual Studio Tools for Universal Windows apps allow you to build a single universal app experience that can reach every device running Windows 10: phone, tablet, PC, and more. It includes the Microsoft Windows 10 Software Development Kit.
WiX Toolset Visual Studio Extension 0.9.17.13693
WiX Toolset Visual Studio Extension version 0.9.17.13693
Copyright (c) .NET Foundation and contributors. All rights reserved.
Xamarin 22.214.171.1243 (c871575)
Visual Studio extension to enable development for Xamarin.iOS and Xamarin.Android.
Xamarin.Android SDK 126.96.36.199 (448f54f)
Xamarin.Android Reference Assemblies and MSBuild support.
Xamarin.iOS and Xamarin.Mac SDK 10.10.0.30 (30b6e87)
Xamarin.iOS and Xamarin.Mac Reference Assemblies and MSBuild support.
=== Visual Studio Professional 2017 for Mac ===
Version 7.0 (build 3146)
Installation UUID: 5782cfba-0b27-4bcc-8621-d13ae60b90a2
Mono 188.8.131.52 (2017-02/9667aa6) (64-bit)
GTK+ 2.24.23 (Raleigh theme)
Package version: 500000100
=== NuGet ===
=== .NET Core ===
MSBuild SDKs: /Library/Frameworks/Mono.framework/Versions/5.0.0/lib/mono/msbuild/15.0/bin/Sdks
=== Xamarin.Profiler ===
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler
=== Xamarin.Android ===
=== Xamarin Inspector ===
=== Apple Developer Tools ===
Xcode 8.3.2 (12175)
=== Xamarin.iOS ===
Version: 10.10.0.33 (Visual Studio Professional)
Build date: 2017-05-05 18:11:38-0400
=== Xamarin.Mac ===
Version: 184.108.40.206 (Visual Studio Professional)
=== Build Information ===
Release ID: 700003146
Git revision: 7553fda2e327d15807298d444007896e5b975dba
Build date: 2017-05-09 12:12:36-04
Xamarin addins: c3d580752be79fc902422f1d55d1cdc2d8b98799
Build lane: monodevelop-lion-d15-2
=== Operating System ===
Mac OS X 10.12.4
Darwin 16.5.0 Darwin Kernel Version 16.5.0
Fri Mar 3 16:52:33 PST 2017
Why are you referencing your own mscorlib.dll?
This is likely to cause all sorts of trouble, because the runtime is very tied to the mscorlib.dll internals.
Because previously allowing Xamarin do implicitly include it would generated duplicate symbol errors. Defining NoStdLib and including mscorlib.dll manually resolved the issue.
"Referencing our own" isn't what's going on here, we just reference the Xamarin.iOS/Xamarin.Android mscorlib directly (which I assume it would do normally, minus something else?) just without the errors we were once getting.
Since 15.2, we've had to remove NoStdLib and our manual reference, but now it gives the message in the OP.
1. What's NoStdLib for?
2. Why doesn't it work anymore?
3. Why do we have this warning even though we're now doing this the "right way"
Now that Xamarin updates are tied to VS, it's getting frustrating dealing with all the idiosyncrasies and outright bugs that come with every release, whereas before it was easier to simply not update Xamarin :(
(In reply to Jahmai from comment #2)
> Because previously allowing Xamarin do implicitly include it would generated
> duplicate symbol errors. Defining NoStdLib and including mscorlib.dll
> manually resolved the issue.
OK, this is the problem we need to fix then, you shouldn't have to do this.
Can you please attach your full build log?
To get full build logs just set the log verbosity to diagnostic at the following locations:
- On Visual Studio for Windows: Tools > Options > Projects and Solutions > Build and Run
- You also want to add `-v -v -v -v` to the mtouch additional arguments by right-clicking the project in the solution explorer and selecting `Properties`.
Well the duplicate symbols error is not a problem anymore since 15.2. Now the problem is just this message:
"C:\Program Files (x86)\Microsoft Visual Studio\2017\Professional\MSBuild\Xamarin\iOS\Xamarin.iOS.Common.targets(747, 3): Tool exited with code: 134. Output: warning MT0109: The assembly 'mscorlib.dll' was loaded from a different path than the provided path (provided path: /Users/xxx/Library/Caches/Xamarin/mtbs/builds/xxx/eb778e30a80662a3fd05d0855a9574ed/bin/Ad-Hoc-Test/mscorlib.dll, actual path: /Library/Frameworks/Xamarin.iOS.framework/Versions/10.10.0.33/lib/mono/Xamarin.iOS/mscorlib.dll)."
Which is caused by the default, implicitly included mscorlib.dll.
I'll run it with the arguments you suggested and give the output.
We have not received the requested information. If you are still experiencing this issue please provide all the requested information and re-open the bug report. Thanks!