Dependencies erroneously loaded from GAC first in Windows PowerShell

Issue Description

Powershell services appears to crash on launch with ‘Missing method exception:’

Exception calling "StartLogging" with "2" argument(s): "Method not found: 'Serilog.LoggerConfiguration Serilog.Configuration.LoggerSinkConfiguration.Wrap(Serilog.Configuration.LoggerSinkConfiguration, System.Func`2<Serilog.Core.ILogEventSink,Serilog.Core.ILogEventSink>, System.Action`1<Serilog.Configuration.LoggerSinkConfiguration>, Serilog.Events.LogEventLevel, Serilog.Core.LoggingLevelSwitch)'."
   at System.Management.Automation.ExceptionHandlingOps.CheckActionPreference(FunctionContext funcContext, Exception exception)
   at System.Management.Automation.Interpreter.ActionCallInstruction`2.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.EnterTryCatchFinallyInstruction.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.Interpreter.Run(InterpretedFrame frame)
   at System.Management.Automation.Interpreter.LightLambda.RunVoid1[T0](T0 arg0)
   at System.Management.Automation.PSScriptCmdlet.RunClause(Action`1 clause, Object dollarUnderbar, Object inputToProcess)
   at System.Management.Automation.PSScriptCmdlet.DoEndProcessing()
   at System.Management.Automation.CommandProcessorBase.Complete()
Method not found: 'Serilog.LoggerConfiguration Serilog.Configuration.LoggerSinkConfiguration.Wrap(Serilog.Configuration.LoggerSinkConfiguration, System.Func`2<Serilog.Core.ILogEventSink,Serilog.Core.ILogEventSink>, System.Action`1<Serilog.Configuration.LoggerSinkConfiguration>, Serilog.Events.LogEventLevel, Serilog.Core.LoggingLevelSwitch)'.
   at Serilog.LoggerConfigurationAsyncExtensions.Async(LoggerSinkConfiguration loggerSinkConfiguration, Action`1 configure, IAsyncLogEventSinkMonitor monitor, Int32 bufferSize, Boolean blockWhenFull)
   at Microsoft.PowerShell.EditorServices.Utility.Logging.Builder.Build()
   at Microsoft.PowerShell.EditorServices.Host.EditorServicesHost.StartLogging(String logFilePath, LogLevel logLevel)
   at CallSite.Target(Closure , CallSite , Object , Object , Object )

Attached Logs

Powershell-logs.zip

Environment Information

Visual Studio Code

Name	Version
Operating System	Windows_NT x64 10.0.17763
VSCode	1.36.1
PowerShell Extension Version	2019.5.0

PowerShell Information

Name	Value
PSVersion	5.1.17763.316
PSEdition	Desktop
PSCompatibleVersions	1.0 2.0 3.0 4.0 5.0 5.1.17763.316
BuildVersion	10.0.17763.316
CLRVersion	4.0.30319.42000
WSManStackVersion	3.0
PSRemotingProtocolVersion	2.3
SerializationVersion	1.1.0.1

Visual Studio Code Extensions

Visual Studio Code Extensions(Click to Expand)

Extension	Author	Version
csharp	ms-vscode	1.21.0
gitblame	waderyan	2.8.1
powershell	ms-vscode	2019.5.0
prettier-vscode	esbenp	1.9.0
tslint	eg2	1.0.44
vscode-antlr4	mike-lischke	2.1.1
vsliveshare	ms-vsliveshare	1.0.540

[rjmholt]

I know this is the older issue, but https://github.com/PowerShell/vscode-powershell/issues/2538 has some more pertinent discussion so I’ll deduplicate to that and pin that one.

Loading from the GAC first is a by-design behaviour in .NET Framework that we can’t work around and the issue is that Serilog’s assembly versioning is deliberately broken.

The solution for us is likely to remove Serilog.

[rjmholt]

Ah nice hunch! It’s a bug on our part then; we only add the types we immediately call into on startup and let them load their dependencies as they go. From this it sounds like that’s fragile and we should eagerly load everything (although in PS 6+ this isn’t a problem actually)