doesn't have a size known at compile-time for Vector of own struct

I am writing my first Rust program (after hello world). I created a simple struct to wrap an "ImageFile" - further logic will be added:

use std::path::Path;

pub struct ImageFile {
    size: u64,
    path: Path,
}

First i needed to put "Path" as last field. Because size - is of course - not known at runtime.
I need the type to be able to expose certain "meta data" about an image file, like type, extension etc.

The problem is: wherever i want to use Vec<ImageFile> i get an error like

error[E0277]: the size for values of type `[u8]` cannot be known at compilation time
   --> src\image\FileIndex.rs:7:12
    |
7   |     files: Vec<ImageFile>,
    |            ^^^^^^^^^^^^^^ doesn't have a size known at compile-time
    |

this is from

use std::{fs};
use crate::index;
use self::super::ImageFile::ImageFile as ImageFile;
/// index of all files for all given dircetories
pub struct FileIndex {
    folders: Vec<String>,
    files: Vec<ImageFile>, //first error here
}

impl FileIndex  {
    pub fn new(folders: Vec<String>) -> FileIndex {
        FileIndex {
            folders,
            files: index(),
        }
    }
...

This creates an index of all image files for the given folders.

What is the best way to fix this for my use case?

This is the best explanation I can find.

As explained in the article Path Implementation works only for references for unsized types.

Using PathBuf only makes sense if you want to mutate the path for some reason.

The best you can do is defining the ImageFile struct as follows.

pub struct ImageFile <'a> {
    size: u64,
    path: &'a Path,
}