warning: useless conversion to the same type: `std::env::VarsOs`
   --> src/toolbox/tool.rs:302:23
    |
302 |           let new_env = env::vars_os()
    |  _______________________^
303 | |             .into_iter()
    | |________________________^ help: consider removing `.into_iter()`: `env::vars_os()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#useless_conversion
    = note: `#[warn(clippy::useless_conversion)]` on by default

warning: the borrowed expression implements the required traits
   --> src/toolbox/tool.rs:281:40
    |
281 |         let mut command = Command::new(&bin);
    |                                        ^^^^ help: change this to: `bin`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrows_for_generic_args
    = note: `#[warn(clippy::needless_borrows_for_generic_args)]` on by default

warning: use of `unwrap_or_else` to construct default value
   --> src/completion/zsh.rs:697:39
    |
697 |                 value_completion(arg).unwrap_or_else(|| "".to_string())
    |                                       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try: `unwrap_or_default()`
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#unwrap_or_default
    = note: `#[warn(clippy::unwrap_or_default)]` on by default

warning: dereferencing a tuple pattern where every element takes a reference
   --> src/completion/zsh.rs:254:9
    |
254 |     for &(ref name, ref bin_name) in &subcommand_names {
    |         ^^^^^^^^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrowed_reference
help: try removing the `&` and `ref` parts
    |
254 -     for &(ref name, ref bin_name) in &subcommand_names {
254 +     for (name, bin_name) in &subcommand_names {
    |

warning: dereferencing a tuple pattern where every element takes a reference
   --> src/completion/zsh.rs:136:9
    |
136 |     for &(_, ref bin_name) in &all_subcommands {
    |         ^^^^^^^^^^^^^^^^^^
    |
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_borrowed_reference
    = note: `#[warn(clippy::needless_borrowed_reference)]` on by default
help: try removing the `&` and `ref` parts
    |
136 -     for &(_, ref bin_name) in &all_subcommands {
136 +     for (_, bin_name) in &all_subcommands {
    |

warning: use of `format!` to build up a string from an iterator
   --> src/cmd/shell.rs:260:25
    |
260 | /                         err_msg
261 | |                             .split_inclusive('\n')
262 | |                             .map(|x| format!("# {}", x))
263 | |                             .collect::<String>(),
    | |________________________________________________^
    |
help: call `fold` instead
   --> src/cmd/shell.rs:262:30
    |
262 | ...                   .map(|x| format!("# {}", x))
    |                        ^^^
help: ... and use the `write!` macro here
   --> src/cmd/shell.rs:262:38
    |
262 | ...                   .map(|x| format!("# {}", x))
    |                                ^^^^^^^^^^^^^^^^^^
    = note: this can be written more efficiently by appending to a `String` directly
    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#format_collect
    = note: `#[warn(clippy::format_collect)]` on by default