PCI express and NIOS

I had a NIOS system working with my custom peripheral this morning on the transceiver starter kit this morning.

I then added a PCI express interface and had to modify the design a bit so I could fit it.

I then recompiled the NIOS and got....

undefined reference to `alt_ic_isr_register'

I see that #define ALT_ENHANCED_INTERRUPT_API_PRESENT is missing from the system.h file for some reason.


Any ideas?