GC unsafe means you're using a mutable variable from outside of thread scope. Very likely you're using a global variable or such which not local to that invoked thread.
For safer solution, change your code to remove any instance of mutable shared variables. For unsafe and not recommended solution, use `--threadAnalysis:off` when you compile your code. Just aware that you'll frequently find segfault if you do this, or worse, you get race-conditioned data.
