Recently print_r() does not fully works as documented "Prints human-readable information about a variable". If there's a BOOL variable, no human readable output appears. I suggest to change this and make print_r() output "(BOOL) TRUE" or "(BOOL) FALSE)" depending on the value of BOOL variable (the "(BOOL)" prefix is to differ these from strings "TRUE/FALSE" (just-in-case ;). Since print_r() is often used for debugging purpose, such fix could simplify it.