message: switch to my xargo fork, because that one works with current libstd
diff: @@ -133,7 +133,11 @@ fn xargo_version() -> Option<(u32, u32, u32)> {
  (split.next().expect("malformed `xargo --version` output: empty"),
  split.next().expect("malformed `xargo --version` output: not at least two words"))
  };
  - if name != "xargo" {
  + if name == "xargo" {
  + // This is the upstream version which is currently broken, we need our fork.
  + return None;
  + }
  + if name != "xargo-rj" {
  panic!("malformed `xargo --version` output: application name is not `xargo`");
  }
  let mut version_pieces = version.split('.');
  @@ -183,11 +187,11 @@ fn setup(ask_user: bool) {
  let xargo = xargo_version();
  if xargo.map_or(true, |v| v < (0, 3, 13)) {
  if ask_user {
  - ask("It seems you do not have a recent enough xargo installed. I will run `cargo install xargo -f`. Proceed?");
  + ask("It seems you do not have a recent enough xargo installed. I will run `cargo install --git https://github.com/RalfJung/xargo -f`. Proceed?");
  } else {
  - println!("Installing xargo: `cargo install xargo -f`");
  + println!("Installing xargo: `cargo install --git https://github.com/RalfJung/xargo -f`");
  }
  - if !Command::new("cargo").args(&["install", "xargo", "-f"]).status().unwrap().success() {
  + if !Command::new("cargo").args(&["install", "--git", "https://github.com/RalfJung/xargo", "-f"]).status().unwrap().success() {
  show_error(format!("Failed to install xargo"));
  }
  }
  