Something from a few weeks ago on HN. "How To Know if Your Cofounder Will Quit on You" https://medium.com/what-i-learned-building/96540ba28355

There was also a story 3-6 months ago here. The story was the co-founder quit while OP spent all his time and money in the product. Boom. That was it for him. Another story was the co-founder quit the night before pitching to investor...