Compiling Error with interrupt service routines for ATtiny using xc8 - c

Question

I am working on a project using an ATtiny 202 and I am nearly done with my programming, but I have run into a large problem. I can't create any ISRs, because I always get a compiler error.
I am using the newest version of MPLABX IDE (5.35) (yes it is for pic and avr mcus) and the second newest version of the xc8 compiler (v2.10). I cannot use the newest version of the compiler, because that is for some reason missing the device header for the ATtiny 202. (I had a different thread about that problem a while ago)
I have created the ISRs exactly like described in the XC8 Manual, and the IDE doesn't mark it as a problem either, but when I then try to compile the program I always get a compiler error.
Here is one of my ISRs:
void __interrupt (RTC_PIT_vect_num) pit_int(void){
onPIT(); //Run the function
RTC.PITINTFLAGS = 0x0; //and clear the interrupt flags
}
The IDE marks the RTC_PIT_vect_num blue and correctly recognizes it, as it is defined in the device header.
When I try to compile it, I get this error message, and the build fails:
main.c:864:19: error: expected declaration specifiers or '...' before numeric constant
void __interrupt (RTC_PIT_vect_num) pit_int(void){
^
I dont know what exactly the problem is and how to solve it.
For comparison, here is an example from the "XC8 User Guide for AVR", page 83:
void __interrupt(SPI_STC_vect_num) spi_Isr(void) {
process(SPI_SlaveReceive());
return;
}
As you can see, the structure of the function is exactly the same as in my own ISR.
Does someone have an idea what the problem is or may be and how to fix it?

Answer 1

Fixed:
I had posted this question on the microchip forum as well, as no one here seemed to be able to help.
So I figured out that the problem was that in the project properties under
XC8 Global Options -> XC8 Compiler -> Option categories: Preprocessing and messages
the option "Use CCI Syntax" was disabled. This needs to be enabled for the __interrupt to work.