Can someone help me debug a Windows memory leak?

I am writing a Go playing program, but it has a memory leak on Windows. No matter how much I tested it on my VM I couldn't reproduce this memory leak on Linux.

It takes about 1 hour to double RAM usage, and this happens BETWEEN games as well (new game starts, RAM usage still high). So something is not cleared after a game is finished.

Download Go GUI: http://gogui.sourceforge.net/
Use my fork:
GitHub - iopq/iomrascalai: iomrascálaí is an AI for the game of Go/Weiqi/Baduk written in Rust

compile, then run
bin/selfplay-benchmark.bat (edit the path to the gogui-twogtp executable if you put it in a different folder)

First, I want people to confirm that this happens on other machines than my own. Can a few people who use Windows test it for me and confirm? I use 64 bit Windows 7, by the way.