#![no_main] #![no_std] extern crate cortex_m_rt; extern crate panic_semihosting; use cortex_m_rt::{entry, exception}; #[entry] fn foo() -> ! { loop {} } #[exception] //~ ERROR custom attribute panicked //~^ HELP `DefaultHandler` exception must have signature `[unsafe] fn(i16) [-> !]` fn DefaultHandler(_irqn: i16, undef: u32) {}