use remove_file in ensure_file_removed
use remove_file in ensure_file_removed

unit test for utils::remove_file

add a test for utils::ensure_file_removed

newline

comment potential solution

drill down to find error type

remove integration tests, moved to utils.rs

moved tests here

Update src/utils/utils.rs

Co-authored-by: 二手掉包工程师 <rustin.liu@gmail.com>

Update src/utils/utils.rs

Co-authored-by: 二手掉包工程师 <rustin.liu@gmail.com>

add a message to panic

cargo fmt

nodakai/rustup.rs,nodakai/rustup.rs,nodakai/rustup.rs,rust-lang/rustup,rust-lang/rustup,rust-lang/rustup,rust-lang/rustup,nodakai/rustup.rs,rust-lang/rustup,nodakai/rustup.rs