[INFO] crate sknife 0.2.2 is already in cache
[INFO] extracting crate sknife 0.2.2 into work/ex/pr-59199/sources/master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7/reg/sknife/0.2.2
[INFO] extracting crate sknife 0.2.2 into work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/reg/sknife/0.2.2
[INFO] validating manifest of sknife-0.2.2 on toolchain master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of sknife-0.2.2 on toolchain try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing sknife-0.2.2
[INFO] finished frobbing sknife-0.2.2
[INFO] frobbed toml for sknife-0.2.2 written to work/ex/pr-59199/sources/master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7/reg/sknife/0.2.2/Cargo.toml
[INFO] started frobbing sknife-0.2.2
[INFO] finished frobbing sknife-0.2.2
[INFO] frobbed toml for sknife-0.2.2 written to work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/reg/sknife/0.2.2/Cargo.toml
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking sknife-0.2.2 against try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b for pr-59199
[INFO] running `"docker" "create" "-v" "/mnt/crater-raid/crater/work/local/target-dirs/pr-59199/worker-2/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b:/opt/crater/target:rw,Z" "-v" "/mnt/crater-raid/crater/work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/reg/sknife/0.2.2:/opt/crater/workdir:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/crater-raid/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" "+68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 53fcfa38cdc1f4cc02139f935f2001c303158892e6353f9a52b73c2f985b562e
[INFO] running `"docker" "start" "-a" "53fcfa38cdc1f4cc02139f935f2001c303158892e6353f9a52b73c2f985b562e"`
[INFO] [stderr]     Checking sknife v0.2.2 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `std`
[INFO] [stderr]  --> src/collection/zip.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use std;
[INFO] [stderr]   |     ^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/collection/any.rs:40:9
[INFO] [stderr]    |
[INFO] [stderr] 40 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/collection/count.rs:28:9
[INFO] [stderr]    |
[INFO] [stderr] 28 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/collection/find.rs:39:9
[INFO] [stderr]    |
[INFO] [stderr] 39 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `super::*`
[INFO] [stderr]   --> src/collection/flatmap.rs:35:9
[INFO] [stderr]    |
[INFO] [stderr] 35 |     use super::*;
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std`
[INFO] [stderr]  --> src/collection/zip.rs:5:5
[INFO] [stderr]   |
[INFO] [stderr] 5 | use std;
[INFO] [stderr]   |     ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/any.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_attributes)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/any.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/count.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/count.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/find.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/find.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/collection/any.rs:44:13
[INFO] [stderr]    |
[INFO] [stderr] 44 |         let mut list = vec![];
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/flatmap.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/flatmap.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/map.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/map.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/reduce.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/reduce.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/zip.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/zip.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/collection/any.rs:54:13
[INFO] [stderr]    |
[INFO] [stderr] 54 |         let mut list = vec![1, 2, 3, 4];
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/collection/count.rs:32:13
[INFO] [stderr]    |
[INFO] [stderr] 32 |         let mut list: Vec<i32> = vec![];
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/collection/count.rs:38:13
[INFO] [stderr]    |
[INFO] [stderr] 38 |         let mut list = vec![1, 2, 3, 4];
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/collection/find.rs:43:13
[INFO] [stderr]    |
[INFO] [stderr] 43 |         let mut list = vec![];
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/collection/find.rs:53:13
[INFO] [stderr]    |
[INFO] [stderr] 53 |         let mut list = vec![1, 2, 3, 4];
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/any.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_attributes)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/any.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/count.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/count.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/find.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/find.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/flatmap.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/flatmap.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/map.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/map.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/reduce.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/reduce.rs:2:1
[INFO] [stderr]   |
[INFO] [stderr] 2 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused attribute
[INFO] [stderr]  --> src/collection/zip.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: crate-level attribute should be in the root module
[INFO] [stderr]  --> src/collection/zip.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![crate_name = "sknife"]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_map.rs:15:13
[INFO] [stderr]    |
[INFO] [stderr] 15 |         let mut slice = list.as_mut_slice();
[INFO] [stderr]    |             ----^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_map.rs:16:13
[INFO] [stderr]    |
[INFO] [stderr] 16 |         let mut plus_one = |x: i32| x + 1;
[INFO] [stderr]    |             ----^^^^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_map.rs:22:13
[INFO] [stderr]    |
[INFO] [stderr] 22 |         let mut list = vec![1, 2, 3];
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_map.rs:23:13
[INFO] [stderr]    |
[INFO] [stderr] 23 |         let mut plus_one = |x| x + 1;
[INFO] [stderr]    |             ----^^^^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_flatmap.rs:15:13
[INFO] [stderr]    |
[INFO] [stderr] 15 |         let mut slice: &mut [i32] = list.as_mut_slice();
[INFO] [stderr]    |             ----^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_flatmap.rs:16:13
[INFO] [stderr]    |
[INFO] [stderr] 16 |         let mut plus_one = |x: &mut i32| vec![*x];
[INFO] [stderr]    |             ----^^^^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_flatmap.rs:22:13
[INFO] [stderr]    |
[INFO] [stderr] 22 |         let mut list = vec![1, 2, 3];
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_flatmap.rs:23:13
[INFO] [stderr]    |
[INFO] [stderr] 23 |         let mut plus_one = |x| vec![x];
[INFO] [stderr]    |             ----^^^^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_reduce.rs:15:13
[INFO] [stderr]    |
[INFO] [stderr] 15 |         let mut fact = |acc: i32, x| acc * x;
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_reduce.rs:21:13
[INFO] [stderr]    |
[INFO] [stderr] 21 |         let mut list: Vec<i32> = (1..50).collect();
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> benches/collections_reduce.rs:22:13
[INFO] [stderr]    |
[INFO] [stderr] 22 |         let mut fact = |acc: i32, x| acc * x;
[INFO] [stderr]    |             ----^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]  --> tests/collections_any.rs:7:9
[INFO] [stderr]   |
[INFO] [stderr] 7 |     let mut list = vec![1, 2, 3, 4];
[INFO] [stderr]   |         ----^^^^
[INFO] [stderr]   |         |
[INFO] [stderr]   |         help: remove this `mut`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]  --> tests/collections_find.rs:7:9
[INFO] [stderr]   |
[INFO] [stderr] 7 |     let mut list = vec![1, 3, 4, 7, 3, 9];
[INFO] [stderr]   |         ----^^^^
[INFO] [stderr]   |         |
[INFO] [stderr]   |         help: remove this `mut`
[INFO] [stderr]   |
[INFO] [stderr]   = note: #[warn(unused_mut)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.85s
[INFO] running `"docker" "inspect" "53fcfa38cdc1f4cc02139f935f2001c303158892e6353f9a52b73c2f985b562e"`
[INFO] running `"docker" "rm" "-f" "53fcfa38cdc1f4cc02139f935f2001c303158892e6353f9a52b73c2f985b562e"`
[INFO] [stdout] 53fcfa38cdc1f4cc02139f935f2001c303158892e6353f9a52b73c2f985b562e