[INFO] crate rusty-santa 0.1.0 is already in cache
[INFO] extracting crate rusty-santa 0.1.0 into work/ex/clippy-test-run/sources/stable/reg/rusty-santa/0.1.0
[INFO] extracting crate rusty-santa 0.1.0 into work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/reg/rusty-santa/0.1.0
[INFO] validating manifest of rusty-santa-0.1.0 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 rusty-santa-0.1.0 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 rusty-santa-0.1.0
[INFO] finished frobbing rusty-santa-0.1.0
[INFO] frobbed toml for rusty-santa-0.1.0 written to work/ex/clippy-test-run/sources/stable/reg/rusty-santa/0.1.0/Cargo.toml
[INFO] started frobbing rusty-santa-0.1.0
[INFO] finished frobbing rusty-santa-0.1.0
[INFO] frobbed toml for rusty-santa-0.1.0 written to work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/reg/rusty-santa/0.1.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+stable" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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 rusty-santa-0.1.0 against stable for clippy-test-run
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/clippy-test-run/worker-4/stable:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/clippy-test-run/sources/stable/reg/rusty-santa/0.1.0:/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] e36e16dd3a9c779ea60ccb5fb925a92d493b34d6743d69a1ccc949ee03c52bbc
[INFO] running `"docker" "start" "-a" "e36e16dd3a9c779ea60ccb5fb925a92d493b34d6743d69a1ccc949ee03c52bbc"`
[INFO] [stderr]     Checking rusty-santa v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/lib.rs:55:13
[INFO] [stderr]    |
[INFO] [stderr] 55 |             keys: keys,
[INFO] [stderr]    |             ^^^^^^^^^^ help: replace it with: `keys`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::redundant_field_names)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/lib.rs:56:13
[INFO] [stderr]    |
[INFO] [stderr] 56 |             indexes: indexes,
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^ help: replace it with: `indexes`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/lib.rs:57:13
[INFO] [stderr]    |
[INFO] [stderr] 57 |             data: data,
[INFO] [stderr]    |             ^^^^^^^^^^ help: replace it with: `data`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]    --> src/lib.rs:157:48
[INFO] [stderr]     |
[INFO] [stderr] 157 |         let constraint = Constraint::Exclude { from: from, to: to };
[INFO] [stderr]     |                                                ^^^^^^^^^^ help: replace it with: `from`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]    --> src/lib.rs:157:60
[INFO] [stderr]     |
[INFO] [stderr] 157 |         let constraint = Constraint::Exclude { from: from, to: to };
[INFO] [stderr]     |                                                            ^^^^^^ help: replace it with: `to`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]    --> src/lib.rs:163:52
[INFO] [stderr]     |
[INFO] [stderr] 163 |         let constraint = Constraint::ExcludePair { a: a, b: b };
[INFO] [stderr]     |                                                    ^^^^ help: replace it with: `a`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]    --> src/lib.rs:163:58
[INFO] [stderr]     |
[INFO] [stderr] 163 |         let constraint = Constraint::ExcludePair { a: a, b: b };
[INFO] [stderr]     |                                                          ^^^^ help: replace it with: `b`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/lib.rs:55:13
[INFO] [stderr]    |
[INFO] [stderr] 55 |             keys: keys,
[INFO] [stderr]    |             ^^^^^^^^^^ help: replace it with: `keys`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::redundant_field_names)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/lib.rs:56:13
[INFO] [stderr]    |
[INFO] [stderr] 56 |             indexes: indexes,
[INFO] [stderr]    |             ^^^^^^^^^^^^^^^^ help: replace it with: `indexes`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]   --> src/lib.rs:57:13
[INFO] [stderr]    |
[INFO] [stderr] 57 |             data: data,
[INFO] [stderr]    |             ^^^^^^^^^^ help: replace it with: `data`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]    --> src/lib.rs:157:48
[INFO] [stderr]     |
[INFO] [stderr] 157 |         let constraint = Constraint::Exclude { from: from, to: to };
[INFO] [stderr]     |                                                ^^^^^^^^^^ help: replace it with: `from`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]    --> src/lib.rs:157:60
[INFO] [stderr]     |
[INFO] [stderr] 157 |         let constraint = Constraint::Exclude { from: from, to: to };
[INFO] [stderr]     |                                                            ^^^^^^ help: replace it with: `to`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]    --> src/lib.rs:163:52
[INFO] [stderr]     |
[INFO] [stderr] 163 |         let constraint = Constraint::ExcludePair { a: a, b: b };
[INFO] [stderr]     |                                                    ^^^^ help: replace it with: `a`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: redundant field names in struct initialization
[INFO] [stderr]    --> src/lib.rs:163:58
[INFO] [stderr]     |
[INFO] [stderr] 163 |         let constraint = Constraint::ExcludePair { a: a, b: b };
[INFO] [stderr]     |                                                          ^^^^ help: replace it with: `b`
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#redundant_field_names
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/lib.rs:244:9
[INFO] [stderr]     |
[INFO] [stderr] 244 |         return Err(AssignError::GivingUp)
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(AssignError::GivingUp)`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::needless_return)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: unneeded return statement
[INFO] [stderr]    --> src/lib.rs:244:9
[INFO] [stderr]     |
[INFO] [stderr] 244 |         return Err(AssignError::GivingUp)
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove `return` as shown: `Err(AssignError::GivingUp)`
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::needless_return)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_return
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `get`
[INFO] [stderr]   --> src/lib.rs:64:5
[INFO] [stderr]    |
[INFO] [stderr] 64 |     pub fn get(&self, x: &str, y: &str) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(dead_code)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `size`
[INFO] [stderr]    --> src/lib.rs:103:5
[INFO] [stderr]     |
[INFO] [stderr] 103 |     pub fn size(&self) -> usize {
[INFO] [stderr]     |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: the loop variable `i` is used to index `data`
[INFO] [stderr]   --> src/lib.rs:50:18
[INFO] [stderr]    |
[INFO] [stderr] 50 |         for i in 0..size {
[INFO] [stderr]    |                  ^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::needless_range_loop)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]    |
[INFO] [stderr] 50 |         for (i, <item>) in data.iter_mut().enumerate().take(size) {
[INFO] [stderr]    |             ^^^^^^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:65:18
[INFO] [stderr]    |
[INFO] [stderr] 65 |         let ix = self.indexes.get(x).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[x]`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::get_unwrap)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:66:18
[INFO] [stderr]    |
[INFO] [stderr] 66 |         let iy = self.indexes.get(y).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[y]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:74:18
[INFO] [stderr]    |
[INFO] [stderr] 74 |         let ix = self.indexes.get(x).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[x]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:82:18
[INFO] [stderr]    |
[INFO] [stderr] 82 |         let ix = self.indexes.get(x).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[x]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:83:18
[INFO] [stderr]    |
[INFO] [stderr] 83 |         let iy = self.indexes.get(y).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[y]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:91:18
[INFO] [stderr]    |
[INFO] [stderr] 91 |         let iy = self.indexes.get(y).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[y]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: you should consider deriving a `Default` implementation for `Group`
[INFO] [stderr]    --> src/lib.rs:138:5
[INFO] [stderr]     |
[INFO] [stderr] 138 | /     pub fn new() -> Self {
[INFO] [stderr] 139 | |         Group {
[INFO] [stderr] 140 | |             people_set: HashSet::new(),
[INFO] [stderr] 141 | |             constraints: vec![],
[INFO] [stderr] 142 | |             max_attempts: 1000,
[INFO] [stderr] 143 | |         }
[INFO] [stderr] 144 | |     }
[INFO] [stderr]     | |_____^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::new_without_default_derive)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default_derive
[INFO] [stderr] help: try this
[INFO] [stderr]     |
[INFO] [stderr] 127 | #[derive(Default)]
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/lib.rs:188:17
[INFO] [stderr]     |
[INFO] [stderr] 188 | /                 match constraint {
[INFO] [stderr] 189 | |                     &Constraint::ExcludePair{ ref a, ref b } => {
[INFO] [stderr] 190 | |                         if !matrix.contains(a) {
[INFO] [stderr] 191 | |                             return Err(AssignError::BadConstraint(format!("Unknown person \"{}\"", a)));
[INFO] [stderr] ...   |
[INFO] [stderr] 207 | |                     }
[INFO] [stderr] 208 | |                 }
[INFO] [stderr]     | |_________________^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::match_ref_pats)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 188 |                 match *constraint {
[INFO] [stderr] 189 |                     Constraint::ExcludePair{ ref a, ref b } => {
[INFO] [stderr] 190 |                         if !matrix.contains(a) {
[INFO] [stderr] 191 |                             return Err(AssignError::BadConstraint(format!("Unknown person \"{}\"", a)));
[INFO] [stderr] 192 |                         }
[INFO] [stderr] 193 |                         if !matrix.contains(b) {
[INFO] [stderr]   ...
[INFO] [stderr] 
[INFO] [stderr] warning: the loop variable `i` is used to index `row`
[INFO] [stderr]    --> src/lib.rs:219:30
[INFO] [stderr]     |
[INFO] [stderr] 219 |                     for i in 0..row.len() {
[INFO] [stderr]     |                              ^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]     |
[INFO] [stderr] 219 |                     for (i, <item>) in row.iter().enumerate() {
[INFO] [stderr]     |                         ^^^^^^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `i`
[INFO] [stderr]    --> src/lib.rs:357:13
[INFO] [stderr]     |
[INFO] [stderr] 357 |         for i in 0..1000 {
[INFO] [stderr]     |             ^ help: consider using `_i` instead
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/lib.rs:279:13
[INFO] [stderr]     |
[INFO] [stderr] 279 |         let mut matrix = Matrix::new(keys);
[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: the loop variable `i` is used to index `data`
[INFO] [stderr]   --> src/lib.rs:50:18
[INFO] [stderr]    |
[INFO] [stderr] 50 |         for i in 0..size {
[INFO] [stderr]    |                  ^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::needless_range_loop)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]    |
[INFO] [stderr] 50 |         for (i, <item>) in data.iter_mut().enumerate().take(size) {
[INFO] [stderr]    |             ^^^^^^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:65:18
[INFO] [stderr]    |
[INFO] [stderr] 65 |         let ix = self.indexes.get(x).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[x]`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(clippy::get_unwrap)] on by default
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:66:18
[INFO] [stderr]    |
[INFO] [stderr] 66 |         let iy = self.indexes.get(y).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[y]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:74:18
[INFO] [stderr]    |
[INFO] [stderr] 74 |         let ix = self.indexes.get(x).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[x]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:82:18
[INFO] [stderr]    |
[INFO] [stderr] 82 |         let ix = self.indexes.get(x).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[x]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:83:18
[INFO] [stderr]    |
[INFO] [stderr] 83 |         let iy = self.indexes.get(y).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[y]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise
[INFO] [stderr]   --> src/lib.rs:91:18
[INFO] [stderr]    |
[INFO] [stderr] 91 |         let iy = self.indexes.get(y).unwrap();
[INFO] [stderr]    |                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `&self.indexes[y]`
[INFO] [stderr]    |
[INFO] [stderr]    = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#get_unwrap
[INFO] [stderr] 
[INFO] [stderr] warning: you should consider deriving a `Default` implementation for `Group`
[INFO] [stderr]    --> src/lib.rs:138:5
[INFO] [stderr]     |
[INFO] [stderr] 138 | /     pub fn new() -> Self {
[INFO] [stderr] 139 | |         Group {
[INFO] [stderr] 140 | |             people_set: HashSet::new(),
[INFO] [stderr] 141 | |             constraints: vec![],
[INFO] [stderr] 142 | |             max_attempts: 1000,
[INFO] [stderr] 143 | |         }
[INFO] [stderr] 144 | |     }
[INFO] [stderr]     | |_____^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::new_without_default_derive)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default_derive
[INFO] [stderr] help: try this
[INFO] [stderr]     |
[INFO] [stderr] 127 | #[derive(Default)]
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: you don't need to add `&` to all patterns
[INFO] [stderr]    --> src/lib.rs:188:17
[INFO] [stderr]     |
[INFO] [stderr] 188 | /                 match constraint {
[INFO] [stderr] 189 | |                     &Constraint::ExcludePair{ ref a, ref b } => {
[INFO] [stderr] 190 | |                         if !matrix.contains(a) {
[INFO] [stderr] 191 | |                             return Err(AssignError::BadConstraint(format!("Unknown person \"{}\"", a)));
[INFO] [stderr] ...   |
[INFO] [stderr] 207 | |                     }
[INFO] [stderr] 208 | |                 }
[INFO] [stderr]     | |_________________^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(clippy::match_ref_pats)] on by default
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_ref_pats
[INFO] [stderr] help: instead of prefixing all patterns with `&`, you can dereference the expression
[INFO] [stderr]     |
[INFO] [stderr] 188 |                 match *constraint {
[INFO] [stderr] 189 |                     Constraint::ExcludePair{ ref a, ref b } => {
[INFO] [stderr] 190 |                         if !matrix.contains(a) {
[INFO] [stderr] 191 |                             return Err(AssignError::BadConstraint(format!("Unknown person \"{}\"", a)));
[INFO] [stderr] 192 |                         }
[INFO] [stderr] 193 |                         if !matrix.contains(b) {
[INFO] [stderr]   ...
[INFO] [stderr] 
[INFO] [stderr] warning: the loop variable `i` is used to index `row`
[INFO] [stderr]    --> src/lib.rs:219:30
[INFO] [stderr]     |
[INFO] [stderr] 219 |                     for i in 0..row.len() {
[INFO] [stderr]     |                              ^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#needless_range_loop
[INFO] [stderr] help: consider using an iterator
[INFO] [stderr]     |
[INFO] [stderr] 219 |                     for (i, <item>) in row.iter().enumerate() {
[INFO] [stderr]     |                         ^^^^^^^^^^^    ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unused `std::result::Result` that must be used
[INFO] [stderr]    --> src/lib.rs:358:13
[INFO] [stderr]     |
[INFO] [stderr] 358 |             group.assign();
[INFO] [stderr]     |             ^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: #[warn(unused_must_use)] on by default
[INFO] [stderr]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.57s
[INFO] running `"docker" "inspect" "e36e16dd3a9c779ea60ccb5fb925a92d493b34d6743d69a1ccc949ee03c52bbc"`
[INFO] running `"docker" "rm" "-f" "e36e16dd3a9c779ea60ccb5fb925a92d493b34d6743d69a1ccc949ee03c52bbc"`
[INFO] [stdout] e36e16dd3a9c779ea60ccb5fb925a92d493b34d6743d69a1ccc949ee03c52bbc