Compiling TGEA Stronghold

I was curious why the docs for TGEA state:

Running the Executable
Do not put the above code in your solution or make any other modifications just yet. If you just compiled under the Debug configuration, go ahead and switch to Release and build (vice versa if you started with Release). Now, we should run the application to see if it works.

What I do not understand is why do the docs tell me to build it twice once as debug and another time as release before running the executable?

Thanks,