Should not be capturing when there is a hotcontrol

This message is occasionally popping up in the console for some of my more complex projects. I'm not sure how to duplicate the issue (so, can't submit it as a bug, if it even is one), so I'm trying to determine what might be causing it. Last time, it popped up when I clicked a compiler warning, in the console.

I THINK it is only happening after I recompile, but I'm not 100% sure of that.

I've searched my own codebase, but nowhere do I reference: https://docs.unity3d.com/ScriptReference/GUIUtility-hotControl.html

I can see it is being called from https://github.com/MattRix/UnityDecompiled/blob/master/UnityEngine/UnityEngine.Experimental.UIElements/EventDispatcher.cs but I'm still not sure what to look for.

Any suggestions on how to prevent this popup would be appreciated.

Edit/addition: The message pops up with a YELLOW icon, indicating he is only a warning. I expect this is why No stack trace is provided. The only way I found that decompiled code linked above, was by searching the entire github project site, for the warning message text.

EDIT: I found, as @Adam-Mechtley requested, some info in the EditorLogs, related to this popup. I'm pasting here (what I think is) the relevant section of the log:

 Refreshing native plugins compatible for Editor in 0.37 ms, found 3 plugins.
 Preloading 1 native plugins for Editor in 0.35 ms.
 Mono: successfully reloaded assembly
 Refreshing native plugins compatible for Editor in 0.41 ms, found 3 plugins.
 Preloading 1 native plugins for Editor in 0.39 ms.
 
 ----- Total AssetImport time: 0.071462s, AssetImport time: 0.000000s, Asset hashing: 0.000000s [0 B, 0.000000 mb/s]
 
 - Completed reload, in  1.046 seconds
 Initializing Unity.PackageManager (PackageManager) v2017.2.0 for Unity v2017.2.0f3
 Registering platform support modules:
 Registered platform support modules in: 0.0347004s.
 Native extension for WindowsStandalone target not found
 Native extension for Android target not found
 Should not be capturing when there is a hotcontrol
 UnityEngine.DebugLogHandler:Internal_Log(LogType, String, Object)
 UnityEngine.DebugLogHandler:LogFormat(LogType, Object, String, Object[])
 UnityEngine.Logger:Log(LogType, Object)
 UnityEngine.Debug:Log(Object)
 UnityEngine.Experimental.UIElements.EventDispatcher:TakeCapture(IEventHandler) (at C:\buildslave\unity\build\Runtime\UIElements\Managed\EventDispatcher.cs:90)
 UnityEngine.Experimental.UIElements.UIElementsUtility:TakeCapture() (at C:\buildslave\unity\build\Runtime\UIElements\Managed\UIElementsUtility.cs:54)
 UnityEngine.GUIUtility:TakeCapture() (at C:\buildslave\unity\build\Runtime\IMGUI\Managed\GUIUtility.cs:113)
 UnityEngine.GUIUtility:Internal_SetHotControl(Int32)
 UnityEngine.GUIUtility:set_hotControl(Int32) (at C:\buildslave\unity\build\Runtime\IMGUI\Managed\GUIUtility.cs:105)
 UnityEditor.ListViewShared:HasMouseDown(InternalListViewState, Rect, Int32) (at C:\buildslave\unity\build\Editor\Mono\GUI\ListViewShared.cs:188)
 UnityEditor.ListViewShared:HasMouseDown(InternalListViewState, Rect) (at C:\buildslave\unity\build\Editor\Mono\GUI\ListViewShared.cs:179)
 UnityEditor.ListViewElementsEnumerator:MoveNext() (at C:\buildslave\unity\build\Editor\Mono\GUI\ListViewShared.cs:370)
 UnityEditor.ConsoleWindow:OnGUI() (at C:\buildslave\unity\build\Editor\Mono\ConsoleWindow.cs:414)
 System.Reflection.MonoMethod:InternalInvoke(Object, Object[], Exception&)
 System.Reflection.MonoMethod:Invoke(Object, BindingFlags, Binder, Object[], CultureInfo) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs:222)
 System.Reflection.MethodBase:Invoke(Object, Object[]) (at /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MethodBase.cs:115)
 UnityEditor.HostView:Invoke(String, Object) (at C:\buildslave\unity\build\Editor\Mono\HostView.cs:285)
 UnityEditor.HostView:Invoke(String) (at C:\buildslave\unity\build\Editor\Mono\HostView.cs:278)
 UnityEditor.HostView:InvokeOnGUI(Rect) (at C:\buildslave\unity\build\Editor\Mono\HostView.cs:245)
 UnityEditor.DockArea:OldOnGUI() (at C:\buildslave\unity\build\Editor\Mono\GUI\DockArea.cs:383)
 UnityEngine.Experimental.UIElements.IMGUIContainer:DoOnGUI(Event) (at C:\buildslave\unity\build\Runtime\UIElements\Managed\IMGUIContainer.cs:127)
 UnityEngine.Experimental.UIElements.IMGUIContainer:HandleEvent(EventBase) (at C:\buildslave\unity\build\Runtime\UIElements\Managed\IMGUIContainer.cs:213)
 UnityEngine.Experimental.UIElements.EventDispatcher:PropagateEvent(VisualElement, EventBase) (at C:\buildslave\unity\build\Runtime\UIElements\Managed\EventDispatcher.cs:343)
 UnityEngine.Experimental.UIElements.EventDispatcher:DispatchEvent(EventBase, BaseVisualElementPanel) (at C:\buildslave\unity\build\Runtime\UIElements\Managed\EventDispatcher.cs:252)
 UnityEngine.Experimental.UIElements.UIElementsUtility:DoDispatch(BaseVisualElementPanel) (at C:\buildslave\unity\build\Runtime\UIElements\Managed\UIElementsUtility.cs:207)
 UnityEngine.Experimental.UIElements.UIElementsUtility:ProcessEvent(Int32, IntPtr) (at C:\buildslave\unity\build\Runtime\UIElements\Managed\UIElementsUtility.cs:72)
 UnityEngine.GUIUtility:ProcessEvent(Int32, IntPtr) (at C:\buildslave\unity\build\Runtime\IMGUI\Managed\GUIUtility.cs:175)
  
 (Filename: /Users/builduser/buildslave/mono/build/mcs/class/corlib/System.Reflection/MonoMethod.cs Line: 222)

EDIT2: bug submitted- https://fogbugz.unity3d.com/default.asp?968044_05s1gv99bq2ofkr8