Hi, no I am not trying to figure it out anymore. Do you need help with your issue?

Hi Lubos, thanks for replying, I just added chmod to yarn binary to fix the problem, I still don’t know what happened to Yarn that caused this.

I was installing Yarn globally and then trying to use it. I solved the issue by using a Docker image shipping with Yarn by default, e.g. node:9.8.0 and removing the npm install -g yarn command. Instead, I can now directly use yarn install without the need to install it first.