Why am I getting this “libxml/tree.h file not found” error?

Question

I just installed Xcode version 4.3.1 and I get this error:

libxml / tree.h file not found

I have also installed Xcode 4.2, and

Answer 1

It appears in 4.3.1, you need to include the Header Search Paths in the Targets as well as the project. I'm not sure if this was an issue with moving from 4.2 to 4.3.1, but I just update to Lion and ran into the same issue.