I have a several XIB files in my iOS project for various custom table cells. I've just added another, but for some reason Xcode will not build this (or any subsequent) XIBs into the project ! 

The appropriate flags are set in the files inspector to include the XIB, and the XIB appears in the correct build phase. All XIBs were working as expected up until this point, and no settings have been altered in the project

![Project Settings](https://i.stack.imgur.com/bE65k.png)

I've experimented with adding more XIBs with different names, but none of them are getting built into the project (verified by inspecting the build application's NIB files). 

![Look Mom, no NIB !](https://i.stack.imgur.com/LSgBz.png)

What is going on ? Is this a bug in Xcode ? Anybody know how to resolve it ?

**Update**

I deleted the derived data directory, and lo and behold the NIB is now appearing in the build product - so I'll chalk this one up as a mysterious Xcode bug.