std::fs::canonicalize result doesn't live long enough

absolutepath needs to remain in scope until the last use of path, because path may contain a reference to absolutepath. In this example, a simple fix is to move the let binding outside of the if block but keep the initialization inside the if block.

use std::fs::canonicalize;
use std::path::Path;
fn main() {
    let mut path = Path::new(".");
    println!("{}", path.display());
    let absolutepath;
    if path.isrelative() {
        absolutepath = canonicalize(path).unwrap();
        path = Path::new(&absolutepath);
    }
    println!("{}", path.display());
}

Note what absolute_path is not initialized if the if block is not entered. That's fine: we're not using the variable itself after the if block (though we are accessing its value indirectly through path). If we were, the compiler would rightfully emit an error that the variable might not be initialized.

use std::path::{PathBuf};
use std::fs::canonicalize;
fn main() {
    let mut path = PathBuf::from(".");
    println!("{}", path.display());
    if path.is_relative() {
        path = canonicalize(path).unwrap();
    }
    println!("{}", path.display());
}