We have to use edition=2018 with codingame

Cargo.toml

@@ -3,7 +3,7 @@ name = "the-fall"
 version = "0.0.1"
 authors = ["Leandro Lisboa Penz <lpenz@lpenz.org>"]
 build = "build.rs"
-edition = "2021"
+edition = "2018"
 
 [lib]
 doctest = false

src/input.rs

@@ -2,6 +2,7 @@
 // This file is subject to the terms and conditions defined in
 // file 'LICENSE', which is part of this source code package.
 
+use std::convert::{TryFrom, TryInto};
 use std::io;
 use std::str::FromStr;
 

tests/episode1.rs

@@ -2,6 +2,7 @@
 // This file is subject to the terms and conditions defined in
 // file 'LICENSE', which is part of this source code package.
 
+use std::convert::TryFrom;
 use std::iter;
 
 use anyhow::Result;