Three20 and Xcode 4 – How to solve Three20.h not found

Update: 18-Feb-2012

Even after the upgrade I have found that certain builds and project settings were flaky. To improve your build speed and reduce all the configuration hassles of using Three20 and Xcode 4 together, check out my latest blog post on Building Static Libraries

Update: 05-Feb-2012

After upgrading to Three20 and following the basic install instructions here, I had no problem building without changing any project settings. Your mileage may vary, however.

I’d still consider myself rather novice to the world of iOS development and the transition from Xcode 3 to Xcode 4 has thrown me for a loop in a few areas. I’ve grown to like storyboards and find Xcode as an IDE to be getting better, but there are some things that drive me nuts. For instance, spending the better part of a day trying to figure out how to get Three20 to work in my project (that was working JUST fine under Xcode 3!).


Follow the instructions provided by Three20 to get yourself oriented with what is going on.

Getting the Build Option to Work:

  • In the Project Navigator view, do the following for each of the Three20 projects (e.g. Three20, Three20Core, etc):
  • Click on the project
  • Go to Build Settings
  • Go to the Deployment section and make sure Skip Install is set to YES for all the configurations (Debug, Internal, Release)
  • Click on the project’s target (under the Targets section) and double check that Skip Install is set to YES for each configuration as well
  • Make sure to repeat these steps in each Three20 project in your project tree

Configuring Build Settings

  • In the Project Navigator view, select your project and then Build Settings
  • Add the two following entries to the Header Search paths and make them the first entries in the list:
    • $(BUILT_PRODUCTS_DIR)/../three20
    • $(BUILT_PRODUCTS_DIR)/../../three20
  • Make sure to set it both in Release and Debug configurations, and that the same build settings appear in your project’s target

Setting the Build Location

Go to Xcode4 Preferences [Cmd + ,] > Locations > Derived Data > Advanced and select Place build products in derived data location.

Clean your project, then build it. Voila.

Comments are closed.