UpdateModsList thread change crashing on Mono

[HebaruSan]

Background

CKAN Version:
c536f13

KSP Version:
1.6.0

Operating System:
Ubuntu 18.04

Have you made any manual changes to your GameData folder (i.e., not via CKAN)?
Yes

Problem

What steps did you take in CKAN?
Compile current master HEAD and run GUI on Linux

What did you expect to happen?
Normal launch

What happened instead?
Weird GUI layout problems and then crash, see below.

It looks like #2617 doesn't work the same on Mono as on Windows.
Please don't publish a release till we fix this.

CKAN error codes (if applicable):

[xcb] Too much data requested from _XRead
[xcb] This is most likely caused by a broken X extension library
[xcb] Aborting, sorry about that.
cli: ../../src/xcb_io.c:732: _XRead: Assertion `!xcb_xlib_too_much_data_requested' failed.
Stacktrace:

  at <unknown> <0xffffffff>
  at (wrapper managed-to-native) System.Windows.Forms.X11Keyboard.XCreateFontSet (intptr,string,intptr&,int&,intptr) [0x0000b] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.X11Keyboard.CreateOverTheSpotXic (intptr,intptr) [0x00023] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.X11Keyboard.CreateXic (intptr,intptr) [0x00042] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.X11Keyboard.CreateXicForWindow (intptr) [0x00000] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.X11Keyboard.FocusIn (intptr) [0x00032] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.XplatUIX11.SetFocus (intptr) [0x00054] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.XplatUI.SetFocus (intptr) [0x00000] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.Control.Select (System.Windows.Forms.Control) [0x0005d] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.Control.FocusInternal (bool) [0x0002a] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.Form.FocusInternal (bool) [0x00016] in <a78030b9a9a543b381a52822d20656d0>:0
  at System.Windows.Forms.Control.Focus () [0x00000] in <a78030b9a9a543b381a52822d20656d0>:0
  at CKAN.Main.SwitchEnabledState () [0x0003e] in <d26c8e7f3da1413293cb83e9482c631b>:0
  at CKAN.Main._UpdateModsList (bool,System.Collections.Generic.IEnumerable`1<CKAN.ModChange>) [0x005aa] in <d26c8e7f3da1413293cb83e9482c631b>:0
  at CKAN.Main/<>c__DisplayClass256_0.<UpdateModsList>b__0 () [0x0001b] in <d26c8e7f3da1413293cb83e9482c631b>:0
  at System.Threading.Tasks.Task.InnerInvoke () <0x0004e>
  at System.Threading.Tasks.Task.Execute () <0x00024>
  at System.Threading.Tasks.Task.ExecutionContextCallback (object) <0x00028>
  at System.Threading.ExecutionContext.RunInternal (System.Threading.ExecutionContext,System.Threading.ContextCallback,object,bool) <0x00171>
  at System.Threading.Tasks.Task.ExecuteWithThreadLocal (System.Threading.Tasks.Task&) <0x000b2>
  at System.Threading.Tasks.Task.ExecuteEntry (bool) <0x0010f>
  at System.Threading.Tasks.Task.System.Threading.IThreadPoolWorkItem.ExecuteWorkItem () <0x00007>
  at System.Threading.ThreadPoolWorkQueue.Dispatch () [0x00074] in <7b0d87324cab49bf96eac679025e77d1>:0
  at System.Threading._ThreadPoolWaitCallback.PerformWaitCallback () <0x00005>
  at (wrapper runtime-invoke) <Module>.runtime_invoke_bool (object,intptr,intptr,intptr) [0x0001e] in <7b0d87324cab49bf96eac679025e77d1>:0