Repairs are a requirement of an FHA loan. This is common in our area. The repairs are a condition of getting the loan. 99% of the time they are done by the Buyer. The best way to protect yourself in a case like this- especially if you are taking out a FHA loan, is- HAVE A HOME INSPECTION. It will point out repairs that are needed and you can negotiate them with the Seller- before FHA can require them to be done.
Sounds like an inspection was not done and now it is up to the Buyer to make the repairs as, usually, Seller has moved on from feeling any obligation to the house.
I do real estate closings- I am a title insurance agent in PA.