Getting the absolute path from a PathBuf

Rust 1.5.0 added std::fs::canonicalize, which sounds pretty close to what you want:

Returns the canonical form of a path with all intermediate components normalized and symbolic links resolved.

Note that, unlike the accepted answer, this removes the ./ from the returned path.

A simple example from my machine:

use std::fs;
use std::path::PathBuf;

fn main() {
    let srcdir = PathBuf::from("./src");
    println!("{:?}", fs::canonicalize(&srcdir));

    let solardir = PathBuf::from("./../solarized/.");
    println!("{:?}", fs::canonicalize(&solardir));
}

Ok("/Users/alexwlchan/Developer/so-example/src")
Ok("/Users/alexwlchan/Developer/solarized")