[lifetime-generate] Crash on assertion failure: `generic_bounds.len() == 0`

[zhengyao-lin]

I was trying to define some traits similar to an iterator, but encountered this isssue (https://play.verus-lang.org/?version=stable&mode=basic&edition=2021&gist=ff5d6a560097dc550a07be84b688629a)

pub trait A {
    type Iter<'a>: B<'a, E = Self::E> where Self: 'a;
    type E;
    
    fn things<'a>(&'a mut self) -> Result<Self::Iter<'a>, Self::E>;
}

pub trait B<'a> {
    type E;
}

thread 'rustc' panicked at rust_verify/src/lifetime_generate.rs:2292:17:
assertion failed: generic_bounds.len() == 0

I think it's probably due to the bound Self: 'a?