Xamarin iOS code signing key not found in keychain

Question

I'm trying to debug my Xamarin.Forms application on a physical iPhone, from my windows machine.

• I have a Mac connected, and an iPhone connected to that Mac
• I have an Apple developer certificate
• I have the device linked to my developer account
• I set up automatic provisioning using Visual Studio (17.0.5)
• I downloaded the generated certificate, and installed it:
  • On the Mac in the System keychain and Login keychain
  • On my windows machine running Visual Studio

When I try to deploy my application in Debug|iPhone, I get the following error:

iOS code signing key 'Apple Development: John Doe (5L4565FZ2L)' not found in keychain.

More details from the build output in Visual Studio:

2>Using "DetectSigningIdentity" task from assembly "C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Xamarin\iOS\..\iOS\Xamarin.iOS.Tasks.dll".
2>Task "DetectSigningIdentity"
2>  DetectSigningIdentity: 2022-02-06T17:49:30.9039262+01:00 - Started
2>  DetectSigningIdentity: 2022-02-06T17:49:30.9039262+01:00 - Initializing
2>  [xma]: Trying to get a Build Connection for Session '6b535ab5f3c9b550fa521b36f236660807d516f929527c4e1cb2a3ecca9ec40d': Xamarin.Messaging.Build.Client.BuildConnection.6b535ab5f3c9b550fa521b36f236660807d516f929527c4e1cb2a3ecca9ec40d, Lifetime: AppDomain
2>  DetectSigningIdentity: 2022-02-06T17:49:30.9039262+01:00 - Initialized
2>  DetectSigningIdentity: 2022-02-06T17:49:30.9039262+01:00 - There's no available inputs to copy to the Mac
2>  DetectSigningIdentity: 2022-02-06T17:49:30.9039262+01:00 - Serializing intputs
2>  DetectSigningIdentity: 2022-02-06T17:49:30.9079268+01:00 - Executing
2>  [xma]: Starting remote task execution for 'Writeful.Mobile.iOS': Xamarin.iOS.Tasks.DetectSigningIdentity
2>  [xma]: Sending Request Xamarin.Messaging.Build.Contracts.ExecuteTaskMessage to topic xvs/build/execute-task/Writeful.Mobile.iOS/6b535ab002fDetectSigningIdentity
2>  [xma]: Received Response of Xamarin.Messaging.Build.Contracts.ExecuteTaskMessage to topic build6b535ab5f3c9b550fa521b36f236660807d516f929527c4e1cb2a3ecca9ec40d47080johndoe/+/xvs/build/execute-task/Writeful.Mobile.iOS/6b535ab002fDetectSigningIdentity
2>  DetectSigningIdentity: 2022-02-06T17:49:30.9499278+01:00 - Logging messages
2>C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Xamarin\iOS\Xamarin.Shared.targets(1566,3): error : iOS code signing key 'Apple Development: John Doe (5L4565FZ2L)' not found in keychain.
2>C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Xamarin\iOS\Xamarin.Shared.targets(1566,3): error :         
2>  DetectSigningIdentity: 2022-02-06T17:49:30.9499278+01:00 - Finished
2>Done executing task "DetectSigningIdentity" -- FAILED.
2>Done building target "_DetectSigningIdentity" in project "Writeful.Mobile.iOS.csproj" -- FAILED.
2>
2>Build FAILED.
2>
2>"C:\Users\johndoe\source\repos\johndoe\writeful-app\Writeful.Mobile.iOS\Writeful.Mobile.iOS.csproj" (Build;BuiltProjectOutputGroup;BuiltProjectOutputGroupDependencies;DebugSymbolsProjectOutputGroup;DebugSymbolsProjectOutputGroupDependencies;DocumentationProjectOutputGroup;DocumentationProjectOutputGroupDependencies;SatelliteDllsProjectOutputGroup;SatelliteDllsProjectOutputGroupDependencies;SGenFilesOutputGroup;SGenFilesOutputGroupDependencies target) (1) ->
2>(_DetectSigningIdentity target) -> 
2>  C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Xamarin\iOS\Xamarin.Shared.targets(1566,3): error : iOS code signing key 'Apple Development: John Doe (5L4565FZ2L)' not found in keychain.
2>C:\Program Files\Microsoft Visual Studio\2022\Community\MSBuild\Xamarin\iOS\Xamarin.Shared.targets(1566,3): error :         
2>
2>    0 Warning(s)
2>    1 Error(s)
2>
2>Time Elapsed 00:00:01.23
========== Build: 1 succeeded, 1 failed, 21 up-to-date, 0 skipped ==========
========== Deploy: 0 succeeded, 0 failed, 0 skipped ==========

I'm not sure which device is missing the signing key, but I assume it is the iPhone, since I installed the certificate on the Mac.

If this is the issue, how can I transfer the certificate to the iPhone? I already tried by deploying an empty app from Xcode on the Mac to the iPhone, but that didn't work.

Answer 1

It took me a while to figure out this issue. I had to export the certificate from my mac to a .p12 file and import the certificate into VS > Tools > options > Xamarin > Apple accounts > View Details > Import certificate and then select the p12 file and import it into VS make sure it display Valid on the status column.