Attaching to GitUserCache events at a time when they might actually be fired

[StanleyGoldman]

Initial access of EntryPoint.Envrionment marks the start of the program and causes the construction of the ApplicationManager.

In this bug, during the construction of ApplicationManager an access to cacheContainer.GitUserCache causes construction of a ManagedCacheBase<T> object.

This object requires information about the current environment. Which causes a re-entrant call into EntryPoint.Environment before the initial call has completed.

The bug can be identified by grabbing a stack trace of when ApplicationManager is being constructed, and looking for the cycle in the stack trace.

UnityEngine.Debug:LogFormat(String, Object[])
GitHub.Unity.EntryPoint:get_ApplicationManager() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/EntryPoint.cs:84)
GitHub.Unity.BaseWindow:Awake() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/UI/BaseWindow.cs:49)
UnityEditorInternal.InternalEditorUtility:LoadSerializedFileAndForget(String)
UnityEditor.WindowLayout:LoadWindowLayout(String, Boolean)

Creating ApplicationManager ManagedThreadId:1
UnityEngine.Debug:LogFormat(String, Object[])
GitHub.Unity.EntryPoint:get_ApplicationManager() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/EntryPoint.cs:84)
GitHub.Unity.EntryPoint:get_Environment() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/EntryPoint.cs:91)
GitHub.Unity.LocationAttribute:.ctor(String, Location) (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/ScriptObjectSingleton.cs:25)
System.MonoType:GetCustomAttributes(Boolean)
GitHub.Unity.ScriptObjectSingleton`1:GetFilePath() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/ScriptObjectSingleton.cs:115)
GitHub.Unity.ScriptObjectSingleton`1:CreateAndLoad() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/ScriptObjectSingleton.cs:81)
GitHub.Unity.ScriptObjectSingleton`1:get_Instance() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/ScriptObjectSingleton.cs:59)
GitHub.Unity.CacheContainer:get_GitUserCache() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/CacheContainer.cs:173)
GitHub.Unity.User:.ctor(ICacheContainer) (at C:/Users/Spade/Projects/GitHub/Unity/src/GitHub.Api/Git/Repository.cs:653)
GitHub.Unity.DefaultEnvironment:Initialize(String, NPath, NPath, NPath) (at C:/Users/Spade/Projects/GitHub/Unity/src/GitHub.Api/Platform/DefaultEnvironment.cs:51)
GitHub.Unity.EnvironmentCache:get_Environment() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/ApplicationCache.cs:105)
GitHub.Unity.ApplicationManager:get_Environment() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/ApplicationManager.cs:98)
GitHub.Unity.ApplicationManagerBase:Initialize() (at C:/Users/Spade/Projects/GitHub/Unity/src/GitHub.Api/Application/ApplicationManagerBase.cs:29)
GitHub.Unity.ApplicationManager:.ctor(IMainThreadSynchronizationContext) (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/ApplicationManager.cs:21)
GitHub.Unity.EntryPoint:get_ApplicationManager() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/EntryPoint.cs:85)
GitHub.Unity.BaseWindow:Awake() (at C:/Users/Spade/Projects/GitHub/Unity/src/UnityExtension/Assets/Editor/GitHub.Unity/UI/BaseWindow.cs:49)
UnityEditorInternal.InternalEditorUtility:LoadSerializedFileAndForget(String)
UnityEditor.WindowLayout:LoadWindowLayout(String, Boolean)```

[shana]