[INFO] updating cached repository VaclavStebra/rust-book-references-and-borrowing
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/VaclavStebra/rust-book-references-and-borrowing
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/VaclavStebra/rust-book-references-and-borrowing" "work/ex/clippy-test-run/sources/stable/gh/VaclavStebra/rust-book-references-and-borrowing"`
[INFO] [stderr] Cloning into 'work/ex/clippy-test-run/sources/stable/gh/VaclavStebra/rust-book-references-and-borrowing'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/VaclavStebra/rust-book-references-and-borrowing" "work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/VaclavStebra/rust-book-references-and-borrowing"`
[INFO] [stderr] Cloning into 'work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/VaclavStebra/rust-book-references-and-borrowing'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 6a69d6a3a909d36b8b69bc865641a6b3053066d0
[INFO] sha for GitHub repo VaclavStebra/rust-book-references-and-borrowing: 6a69d6a3a909d36b8b69bc865641a6b3053066d0
[INFO] validating manifest of VaclavStebra/rust-book-references-and-borrowing on toolchain stable
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of VaclavStebra/rust-book-references-and-borrowing on toolchain stable+rustflags=-Dclippy::into_iter_on_array
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing VaclavStebra/rust-book-references-and-borrowing
[INFO] finished frobbing VaclavStebra/rust-book-references-and-borrowing
[INFO] frobbed toml for VaclavStebra/rust-book-references-and-borrowing written to work/ex/clippy-test-run/sources/stable/gh/VaclavStebra/rust-book-references-and-borrowing/Cargo.toml
[INFO] started frobbing VaclavStebra/rust-book-references-and-borrowing
[INFO] finished frobbing VaclavStebra/rust-book-references-and-borrowing
[INFO] frobbed toml for VaclavStebra/rust-book-references-and-borrowing written to work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/gh/VaclavStebra/rust-book-references-and-borrowing/Cargo.toml
[INFO] crate VaclavStebra/rust-book-references-and-borrowing has a lockfile. skipping
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] linting VaclavStebra/rust-book-references-and-borrowing against stable for clippy-test-run
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/clippy-test-run/worker-6/stable:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/clippy-test-run/sources/stable/gh/VaclavStebra/rust-book-references-and-borrowing:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+stable" "clippy" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] a2b5339b7ffa6bb7343d514a2ab2931b7cc60c45d02c19d200709dab0559b5ec
[INFO] running `"docker" "start" "-a" "a2b5339b7ffa6bb7343d514a2ab2931b7cc60c45d02c19d200709dab0559b5ec"`
[INFO] [stderr]     Checking rust-book-references-and-borrowing v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: returning the result of a let binding from a block. Consider returning the expression directly.
[INFO] [stderr]   --> src/main.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     s
[INFO] [stderr]    |     ^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::let_and_return)] on by default
[INFO] [stderr] note: this expression can be directly returned
[INFO] [stderr]   --> src/main.rs:51:13
[INFO] [stderr]    |
[INFO] [stderr] 51 |     let s = String::from("hello");
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `r1`
[INFO] [stderr]   --> src/main.rs:20:9
[INFO] [stderr]    |
[INFO] [stderr] 20 |     let r1 = &mut s2;
[INFO] [stderr]    |         ^^ help: consider using `_r1` instead
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: writing `&String` instead of `&str` involves a new object where a slice will do.
[INFO] [stderr]   --> src/main.rs:31:24
[INFO] [stderr]    |
[INFO] [stderr] 31 | fn calculate_length(s: &String) -> usize {
[INFO] [stderr]    |                        ^^^^^^^ help: change this to: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::ptr_arg)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stderr] 
[INFO] [stderr] warning: returning the result of a let binding from a block. Consider returning the expression directly.
[INFO] [stderr]   --> src/main.rs:53:5
[INFO] [stderr]    |
[INFO] [stderr] 53 |     s
[INFO] [stderr]    |     ^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::let_and_return)] on by default
[INFO] [stderr] note: this expression can be directly returned
[INFO] [stderr]   --> src/main.rs:51:13
[INFO] [stderr]    |
[INFO] [stderr] 51 |     let s = String::from("hello");
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#let_and_return
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `r1`
[INFO] [stderr]   --> src/main.rs:20:9
[INFO] [stderr]    |
[INFO] [stderr] 20 |     let r1 = &mut s2;
[INFO] [stderr]    |         ^^ help: consider using `_r1` instead
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: writing `&String` instead of `&str` involves a new object where a slice will do.
[INFO] [stderr]   --> src/main.rs:31:24
[INFO] [stderr]    |
[INFO] [stderr] 31 | fn calculate_length(s: &String) -> usize {
[INFO] [stderr]    |                        ^^^^^^^ help: change this to: `&str`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::ptr_arg)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.75s
[INFO] running `"docker" "inspect" "a2b5339b7ffa6bb7343d514a2ab2931b7cc60c45d02c19d200709dab0559b5ec"`
[INFO] running `"docker" "rm" "-f" "a2b5339b7ffa6bb7343d514a2ab2931b7cc60c45d02c19d200709dab0559b5ec"`
[INFO] [stdout] a2b5339b7ffa6bb7343d514a2ab2931b7cc60c45d02c19d200709dab0559b5ec