Use edition 2018.

Cargo.toml

@@ -8,6 +8,7 @@ license = "MIT OR Apache-2.0"
 name = "cross"
 repository = "https://github.com/rust-embedded/cross"
 version = "0.1.16"
+edition = "2018"
 
 [dependencies]
 atty = "0.2"

src/cargo.rs

@@ -2,8 +2,8 @@ use std::path::{Path, PathBuf};
 use std::process::{Command, ExitStatus};
 use std::{env, fs};
 
-use errors::*;
-use extensions::CommandExt;
+use crate::errors::*;
+use crate::extensions::CommandExt;
 
 #[derive(Debug, Clone, Copy, PartialEq, Eq)]
 pub enum Subcommand {

src/cli.rs

@@ -1,8 +1,8 @@
 use std::env;
 
-use Target;
-use cargo::Subcommand;
-use rustc::TargetList;
+use crate::Target;
+use crate::cargo::Subcommand;
+use crate::rustc::TargetList;
 
 pub struct Args {
     pub all: Vec<String>,

src/docker.rs

@@ -5,11 +5,11 @@ use std::{env, fs};
 use atty::Stream;
 use semver::{Version, VersionReq};
 
-use {Target, Toml};
-use cargo::Root;
-use errors::*;
-use extensions::CommandExt;
-use id;
+use crate::{Target, Toml};
+use crate::cargo::Root;
+use crate::errors::*;
+use crate::extensions::CommandExt;
+use crate::id;
 
 const DOCKER_IMAGES: &[&str] = &include!(concat!(env!("OUT_DIR"), "/docker-images.rs"));
 

src/extensions.rs

@@ -1,6 +1,6 @@
 use std::process::{Command, ExitStatus};
 
-use errors::*;
+use crate::errors::*;
 
 pub trait CommandExt {
     fn run(&mut self, verbose: bool) -> Result<()>;

src/file.rs

@@ -2,7 +2,7 @@ use std::fs::File;
 use std::io::Read;
 use std::path::Path;
 
-use errors::*;
+use crate::errors::*;
 
 pub fn read<P>(path: P) -> Result<String>
     where P: AsRef<Path>

src/interpreter.rs

@@ -1,8 +1,8 @@
 use std::path::Path;
 
-use errors::*;
-use file;
-use Target;
+use crate::errors::*;
+use crate::file;
+use crate::Target;
 
 /// Checks if the interpreters have been registered in the host system
 pub fn is_registered(target: &Target) -> Result<bool> {

src/main.rs

@@ -33,12 +33,12 @@ use std::{env, io, process};
 
 use toml::{Value, value::Table};
 
-use cargo::{Root, Subcommand};
-use errors::*;
-use rustc::{TargetList, VersionMetaExt};
+use self::cargo::{Root, Subcommand};
+use self::errors::*;
+use self::rustc::{TargetList, VersionMetaExt};
 
 #[allow(non_camel_case_types)]
-#[derive(Debug, Clone, Copy, PartialEq)]
+#[derive(Debug, Clone, PartialEq)]
 pub enum Host {
     Other,
 

src/rustc.rs

@@ -3,9 +3,9 @@ use std::process::Command;
 
 use rustc_version::{Version, VersionMeta};
 
-use {Host, Target};
-use errors::*;
-use extensions::CommandExt;
+use crate::{Host, Target};
+use crate::errors::*;
+use crate::extensions::CommandExt;
 
 pub struct TargetList {
     triples: Vec<String>,

src/rustup.rs

@@ -1,8 +1,8 @@
 use std::process::Command;
 
-use Target;
-use errors::*;
-use extensions::CommandExt;
+use crate::Target;
+use crate::errors::*;
+use crate::extensions::CommandExt;
 
 #[derive(Debug)]
 pub struct AvailableTargets {