ICE when fold accumulator type annotation is incorrect

[RyanAlameddine]

The following code snippet causes an internal compiler error on my version of rust (rustc 1.75.0-nightly):

source_iter(vec![1]) 
    -> fold(Vec::new, |accum: Vec<usize>, elem| {accum.push(elem)}) 
    -> assert_eq([vec![1]]);

Note that the mistake is is that accum: Vec<usize> should be accum: &mut Vec<usize>.

Also, I'm curious why the type of accum can't be inferred.

[MingweiSamuel]

Maybe rust-lang/rust#116658