I've used other IDE's in the past but am new to Xcode. I'm trying to bring in a bunch of C code from an open source project. I've imported them into a new Group and the .c files all show up under Implementation Files and the full list of files shows up in the Groups/Files group as well as my project directory in the finder. When I try to include or import one of these header files, code completion even works so I know Xcode is seeing them. But then when I go to build it says "no such file or directory". How can I get these files to import into my code?