I've made a Gatsby starter, and two separate people have reported to me that they are unable to run it, because it gets stuck while building a "development bundle". Neither development nor production build works. I'm unable to reproduce this issue on my own machine, but I would like to fix it for the people who want to use my starter. What could cause Gatsby to get stuck in this step, and is there any way that I could force the issue to reproduce on my machine?