Re: Explaination on GC-safety warning of Nim compiler

[nepeckman]

I'm far from a Nim expert, but I think GC safety is determined by access of 
global variables. Does this section of the manual reference anything useful? 
[https://nim-lang.org/docs/manual.html#threads-gc-safety](https://nim-lang.org/docs/manual.html#threads-gc-safety)