Adding Xamarin.Firebase.iOS.PerformanceMonitoring to a new project causes compilation errors

[MikeOsborn]

Reproduction Steps:

1. Create a new blank Xamarin.Forms iOS app.
2. Add the latest Xamarin.Firebase.iOS.PerformanceMonitoring nuget package
3. Compile the app.

A number of compilation errors occur here are a couple:

• Error MT5210: Native linking failed, undefined symbol: _FIRLogDebug. Please verify that all the necessary frameworks have been referenced and native libraries are properly linked in.
• [APMMeasurement networkUploadCompletionHandlerWithResponse: Error: ] in GoogleAppMeasurement(APMMeasurement_87bdad44f2b9aa68c2d607a36be1b8c5.o)

Environment Information:

=== Visual Studio Community 2019 for Mac ===

Version 8.6.2 (build 6)
Installation UUID: 6b7a8323-55bc-42d4-8863-75f140a95bb6
GTK+ 2.24.23 (Raleigh theme)
Xamarin.Mac 6.18.0.23 (d16-6 / 088c73638)

Package version: 610000104

=== Mono Framework MDK ===

Runtime:
Mono 6.10.0.104 (2019-12/5d03a6fe116) (64-bit)
Package version: 610000104

=== Roslyn (Language Service) ===

3.6.0-3.20210.9+4eafdcb1bcbd8d3573f2ba6065e56d9b9ce4f8a3

=== NuGet ===

Version: 5.6.0.6591

=== .NET Core SDK ===

SDK: /usr/local/share/dotnet/sdk/3.1.300/Sdks
SDK Versions:
3.1.300
3.1.200
3.1.102
3.1.101
MSBuild SDKs: /Library/Frameworks/Mono.framework/Versions/6.10.0/lib/mono/msbuild/Current/bin/Sdks

=== .NET Core Runtime ===

Runtime: /usr/local/share/dotnet/dotnet
Runtime Versions:
3.1.4
3.1.2
3.1.1
2.1.18
2.1.16
2.1.15

=== Xamarin.Profiler ===

Version: 1.6.13.11
Location: /Applications/Xamarin Profiler.app/Contents/MacOS/Xamarin Profiler

=== Updater ===

Version: 11

=== Xamarin Designer ===

Version: 16.6.0.329
Hash: d4f8bcd13
Branch: remotes/origin/d16-6
Build date: 2020-04-24 02:16:02 UTC

=== Apple Developer Tools ===

Xcode 11.5 (16139)
Build 11E608c

=== Xamarin.Mac ===

Xamarin.Mac not installed. Can't find /Library/Frameworks/Xamarin.Mac.framework/Versions/Current/Version.

=== Xamarin.iOS ===

Version: 13.18.2.1 (Visual Studio Community)
Hash: 29c4ea731
Branch: d16-6
Build date: 2020-05-26 17:03:05-0400

=== Xamarin.Android ===

Version: 10.3.1.4 (Visual Studio Community)
Commit: xamarin-android/d16-6/3a10de9
Android SDK: /Users/osbornmi/Library/Developer/Xamarin/android-sdk-macosx
Supported Android versions:
None installed

SDK Tools Version: 26.1.1
SDK Platform Tools Version: 29.0.5
SDK Build Tools Version: 29.0.3

Build Information:
Mono: 165f4b0
Java.Interop: xamarin/java.interop/d16-6@2cab35c
ProGuard: xamarin/proguard@905836d
SQLite: xamarin/sqlite@49232bc
Xamarin.Android Tools: xamarin/xamarin-android-tools/d16-6@bfb66f3

=== Microsoft Mobile OpenJDK ===

Java SDK: /Users/osbornmi/Library/Developer/Xamarin/jdk/microsoft_dist_openjdk_1.8.0.25
1.8.0-25
Android Designer EPL code available here:
https://github.com/xamarin/AndroidDesigner.EPL

=== Android SDK Manager ===

Version: 16.6.0.50
Hash: 5901879
Branch: remotes/origin/d16-6
Build date: 2020-04-30 04:01:22 UTC

=== Android Device Manager ===

Version: 16.6.0.95
Hash: 45d17b5
Branch: remotes/origin/d16-6
Build date: 2020-04-30 04:01:42 UTC

=== Build Information ===

Release ID: 806020006
Git revision: c742dc3fcbf76855738eef57ce41d65f91acbf27
Build date: 2020-05-28 15:22:51-04
Build branch: release-8.6
Xamarin extensions: c742dc3fcbf76855738eef57ce41d65f91acbf27

=== Operating System ===

Mac OS X 10.15.3
Darwin 19.3.0 Darwin Kernel Version 19.3.0
Thu Jan 9 20:58:23 PST 2020
root:xnu-6153.81.5~1/RELEASE_X86_64 x86_64

[MikeOsborn]

I filed this bug using the latest version of Xamarin.iOS at the time; however, the project I'm working on was having the same issue but using an older version of Xamarin.iOS. I upgraded that project to Xamarin.iOS 13.10.0.21 which I downloaded from here: https://github.com/xamarin/xamarin-macios.

I ran into build issues when including this library but was able to get around the issues by adding a reference to Firebase.RemoteConfig.RemoteConfig. Here's an example of how I accomplished that.

    [Foundation.Preserve(AllMembers = true)]
    public class LinkerPleaseInclude
    {
        public void Include(Firebase.RemoteConfig.RemoteConfig remoteConfig)
        {
        }
    }

I have not tried this fix with the latest version of Xamarin.iOS.