I bought a fixer upper to live in with cash. I sold at a substantial loss after realizing excessive repair cost. Do I need to report purchase to IRS?

Yes.  If you sold a house, even if you sold it at a loss, it is best to report it on your return.  You need the "paper trail" and to tell them that it was at a loss.

To enter the Sale of a Home select the following:

1. Federal
2. Income
3. Sale of Home under Less Common Income