[Solaris] mono 4 broken (any winforms app)

[despair86]

despair@sun-pc:~$ monodevelop

Unhandled Exception:
System.TypeInitializationException: An exception was thrown by the type initializer for MonoDevelop.Core.LoggingService ---> System.TimeZoneNotFoundException: Exception of type 'System.TimeZoneNotFoundException' was thrown.
  at System.TimeZoneInfo.get_Local () [0x00000] in <filename unknown>:0
  at System.TimeZoneInfo.GetDateTimeNowUtcOffsetFromUtc (DateTime time, System.Boolean& isAmbiguousLocalDst) [0x00000] in <filename unknown>:0
  at System.DateTime.get_Now () [0x00000] in <filename unknown>:0
  at MonoDevelop.Core.LoggingService..cctor () [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at MonoDevelop.Ide.IdeStartup.Main (System.String[] args, MonoDevelop.Ide.Extensions.IdeCustomizer customizer) [0x00000] in <filename unknown>:0
  at MonoDevelop.Startup.MonoDevelopMain.Main (System.String[] args) [0x00000] in <filename unknown>:0
[ERROR] FATAL UNHANDLED EXCEPTION: System.TypeInitializationException: An exception was thrown by the type initializer for MonoDevelop.Core.LoggingService ---> System.TimeZoneNotFoundException: Exception of type 'System.TimeZoneNotFoundException' was thrown.
  at System.TimeZoneInfo.get_Local () [0x00000] in <filename unknown>:0
  at System.TimeZoneInfo.GetDateTimeNowUtcOffsetFromUtc (DateTime time, System.Boolean& isAmbiguousLocalDst) [0x00000] in <filename unknown>:0
  at System.DateTime.get_Now () [0x00000] in <filename unknown>:0
  at MonoDevelop.Core.LoggingService..cctor () [0x00000] in <filename unknown>:0
  --- End of inner exception stack trace ---
  at MonoDevelop.Ide.IdeStartup.Main (System.String[] args, MonoDevelop.Ide.Extensions.IdeCustomizer customizer) [0x00000] in <filename unknown>:0
  at MonoDevelop.Startup.MonoDevelopMain.Main (System.String[] args) [0x00000] in <filename unknown>:0

haven't been able to use winforms for months
however, it used to work a while back (early '19 at the latest)
using pkgsrc trunk amd64/gcc7 on oi hipster (May '19)+ current patches
(haven't had a chance to build my own with gcc or sunpro yet)