Arguments are currently separated by space, enclosing them in quotes won't help.

Passing custom arguments is convenient when you need to change some project options for Jenkins build, but don't want them to persist in project file. For example when running application tests, following settings often are nice fit: GCC_SYMBOLS_PRIVATE_EXTERN=NO COPY_PHASE_STRIP=NO. Otherwise Release build will usually fail because it won't be able to find application symbols to link with test bundle.