Not hard; once we knew why it broke it was easy to fix. Took half a day to figure out why it was broken though.
Key thing is: these two teams maintaining two separate Dockers aren't part of the same org, so there's no incentives to align either image to not break the other. If they were commercial entities driven by maximizing userbase or revenue, there would be reason for them to minimize breaking each other (especially if they were the same company; then someone's in charge and can tell one team or the other "Fix it or you're fired").
Key thing is: these two teams maintaining two separate Dockers aren't part of the same org, so there's no incentives to align either image to not break the other. If they were commercial entities driven by maximizing userbase or revenue, there would be reason for them to minimize breaking each other (especially if they were the same company; then someone's in charge and can tell one team or the other "Fix it or you're fired").