This is a great observation. It’s good to think about Julia a little differently from “traditional” compiled languages, at least as it currently stands. It essentially compiles on the fly (JIT or AOT… that’s kind of an argument), and redoes this as necessary. This works well enough for interactive computing, but starts to run into problems in other scenarios. Precompilation more-or-less forces compilation when you want it to happen, thereby reducing that first-run pause.
Not sure why there would be a dependency on your C compiler setting?
Section split into PackageCompiler hang
Did you get an error or did it just hang? How long did you wait? It might not be the fastest thing… 
Nonetheless, what you’re seeing is that, for this kind of use case, Julia is currently a little rough around the edges, as we say. But that’s why there’s a fair amount of work going into the compiler.