Error message blames wrong line

[vchekan]

The code below blames the last line for the error where in fact error is in the previous one.
The error message makes no sense because x4 type is specified explicitly and no iterator is present anymore.

fn main() {
    let v = vec![1_f64, 2.2_f64];
    let mut fft: Vec<Vec<f64>> = vec![];

    let x1: &[f64] = &v;
    let x2 = x1.into_iter();
    let x3 = x2.rev();
    let x4: Vec<f64> = x3.collect();    // <-- mistake is here
    fft.push(x4);                                 // <-- but error blames this line
}

--> src/main.rs:9:14
  |
9 |     fft.push(x4);
  |              ^^ a collection of type `std::vec::Vec<f64>` cannot be built from `std::iter::Iterator<Item=&f64>`