[INFO] crate outcome-sim 0.1.0 is already in cache [INFO] extracting crate outcome-sim 0.1.0 into work/ex/clippy-test-run/sources/stable/reg/outcome-sim/0.1.0 [INFO] extracting crate outcome-sim 0.1.0 into work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/reg/outcome-sim/0.1.0 [INFO] validating manifest of outcome-sim-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 outcome-sim-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 outcome-sim-0.1.0 [INFO] finished frobbing outcome-sim-0.1.0 [INFO] frobbed toml for outcome-sim-0.1.0 written to work/ex/clippy-test-run/sources/stable/reg/outcome-sim/0.1.0/Cargo.toml [INFO] started frobbing outcome-sim-0.1.0 [INFO] finished frobbing outcome-sim-0.1.0 [INFO] frobbed toml for outcome-sim-0.1.0 written to work/ex/clippy-test-run/sources/stable+rustflags=-Dclippy%3A%3Ainto_iter_on_array/reg/outcome-sim/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 outcome-sim-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-5/stable:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/clippy-test-run/sources/stable/reg/outcome-sim/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] 72c04c502df5ced7b6f926467030e52354f71ae4b79b1ea240603c98641c906d [INFO] running `"docker" "start" "-a" "72c04c502df5ced7b6f926467030e52354f71ae4b79b1ea240603c98641c906d"` [INFO] [stderr] Checking outcome-sim v0.1.0 (/opt/crater/workdir) [INFO] [stderr] warning: redundant field names in struct initialization [INFO] [stderr] --> src/core.rs:187:13 [INFO] [stderr] | [INFO] [stderr] 187 | element_type: element_type, [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `element_type` [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/core.rs:187:13 [INFO] [stderr] | [INFO] [stderr] 187 | element_type: element_type, [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^ help: replace it with: `element_type` [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: returning the result of a let binding from a block. Consider returning the expression directly. [INFO] [stderr] --> src/core.rs:34:9 [INFO] [stderr] | [INFO] [stderr] 34 | db [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/core.rs:26:18 [INFO] [stderr] | [INFO] [stderr] 26 | let db = DataBase { [INFO] [stderr] | __________________^ [INFO] [stderr] 27 | | props: HashMap::new(), [INFO] [stderr] 28 | | regions: HashMap::new(), [INFO] [stderr] 29 | | orgs: HashMap::new(), [INFO] [stderr] 30 | | globals: HashMap::new(), [INFO] [stderr] 31 | | universal: Universal::new("UNIVERSAL"), [INFO] [stderr] 32 | | }; [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: returning the result of a let binding from a block. Consider returning the expression directly. [INFO] [stderr] --> src/parser.rs:75:5 [INFO] [stderr] | [INFO] [stderr] 75 | world [INFO] [stderr] | ^^^^^ [INFO] [stderr] | [INFO] [stderr] note: this expression can be directly returned [INFO] [stderr] --> src/parser.rs:72:17 [INFO] [stderr] | [INFO] [stderr] 72 | let world = initialize_all(registered, SimInstance::new()); [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: returning the result of a let binding from a block. Consider returning the expression directly. [INFO] [stderr] --> src/core.rs:34:9 [INFO] [stderr] | [INFO] [stderr] 34 | db [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/core.rs:26:18 [INFO] [stderr] | [INFO] [stderr] 26 | let db = DataBase { [INFO] [stderr] | __________________^ [INFO] [stderr] 27 | | props: HashMap::new(), [INFO] [stderr] 28 | | regions: HashMap::new(), [INFO] [stderr] 29 | | orgs: HashMap::new(), [INFO] [stderr] 30 | | globals: HashMap::new(), [INFO] [stderr] 31 | | universal: Universal::new("UNIVERSAL"), [INFO] [stderr] 32 | | }; [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: returning the result of a let binding from a block. Consider returning the expression directly. [INFO] [stderr] --> src/parser.rs:75:5 [INFO] [stderr] | [INFO] [stderr] 75 | world [INFO] [stderr] | ^^^^^ [INFO] [stderr] | [INFO] [stderr] note: this expression can be directly returned [INFO] [stderr] --> src/parser.rs:72:17 [INFO] [stderr] | [INFO] [stderr] 72 | let world = initialize_all(registered, SimInstance::new()); [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: you should consider adding a `Default` implementation for `core::DataBase` [INFO] [stderr] --> src/core.rs:25:5 [INFO] [stderr] | [INFO] [stderr] 25 | / pub fn new() -> DataBase { [INFO] [stderr] 26 | | let db = DataBase { [INFO] [stderr] 27 | | props: HashMap::new(), [INFO] [stderr] 28 | | regions: HashMap::new(), [INFO] [stderr] ... | [INFO] [stderr] 34 | | db [INFO] [stderr] 35 | | } [INFO] [stderr] | |_____^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::new_without_default)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default [INFO] [stderr] help: try this [INFO] [stderr] | [INFO] [stderr] 24 | impl Default for core::DataBase { [INFO] [stderr] 25 | fn default() -> Self { [INFO] [stderr] 26 | Self::new() [INFO] [stderr] 27 | } [INFO] [stderr] 28 | } [INFO] [stderr] | [INFO] [stderr] [INFO] [stderr] warning: usage of `contains_key` followed by `insert` on a `HashMap` [INFO] [stderr] --> src/core.rs:38:9 [INFO] [stderr] | [INFO] [stderr] 38 | / if self.props.contains_key(&prop_addr) { [INFO] [stderr] 39 | | println!( [INFO] [stderr] 40 | | "Couldn't add prop to database because key already exists: {:?}", [INFO] [stderr] 41 | | &prop_addr [INFO] [stderr] ... | [INFO] [stderr] 44 | | self.props.insert(prop_addr, prop); [INFO] [stderr] 45 | | } [INFO] [stderr] | |_________^ help: consider using: `self.props.entry(prop_addr)` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::map_entry)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_entry [INFO] [stderr] [INFO] [stderr] warning: you should use the `starts_with` method [INFO] [stderr] --> src/core.rs:147:12 [INFO] [stderr] | [INFO] [stderr] 147 | if self.address.chars().next().unwrap() != '/' [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: like this: `!self.address.starts_with('/')` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::chars_next_cmp)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#chars_next_cmp [INFO] [stderr] [INFO] [stderr] warning: you should consider adding a `Default` implementation for `core::SimInstance` [INFO] [stderr] --> src/core.rs:279:5 [INFO] [stderr] | [INFO] [stderr] 279 | / pub fn new() -> SimInstance { [INFO] [stderr] 280 | | SimInstance { [INFO] [stderr] 281 | | metadata: HashMap::new(), [INFO] [stderr] 282 | | database: DataBase::new(), [INFO] [stderr] 283 | | } [INFO] [stderr] 284 | | } [INFO] [stderr] | |_____^ [INFO] [stderr] | [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default [INFO] [stderr] help: try this [INFO] [stderr] | [INFO] [stderr] 278 | impl Default for core::SimInstance { [INFO] [stderr] 279 | fn default() -> Self { [INFO] [stderr] 280 | Self::new() [INFO] [stderr] 281 | } [INFO] [stderr] 282 | } [INFO] [stderr] | [INFO] [stderr] [INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise [INFO] [stderr] --> src/parser.rs:81:20 [INFO] [stderr] | [INFO] [stderr] 81 | let vec = ®.hashmap.get(obj_type).unwrap(); [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `®.hashmap[obj_type]` [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: writing `&String` instead of `&str` involves a new object where a slice will do. [INFO] [stderr] --> src/parser.rs:91:15 [INFO] [stderr] | [INFO] [stderr] 91 | obj_type: &String, [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: writing `&Vec<_>` instead of `&[_]` involves one more reference and cannot be used with non-Vec-based slices. [INFO] [stderr] --> src/parser.rs:92:11 [INFO] [stderr] | [INFO] [stderr] 92 | list: &Vec, [INFO] [stderr] | ^^^^^^^^^^^^ help: change this to: `&[String]` [INFO] [stderr] | [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg [INFO] [stderr] [INFO] [stderr] warning: you seem to be trying to use match for destructuring a single pattern. Consider using `if let` [INFO] [stderr] --> src/parser.rs:115:5 [INFO] [stderr] | [INFO] [stderr] 115 | / match entity_type { [INFO] [stderr] 116 | | "region" => initialize_entity_region(value, world_buf), [INFO] [stderr] 117 | | _ => (), [INFO] [stderr] 118 | | } [INFO] [stderr] | |_____^ help: try this: `if let "region" = entity_type { initialize_entity_region(value, world_buf) }` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::single_match)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match [INFO] [stderr] [INFO] [stderr] warning: use of `expect` followed by a function call [INFO] [stderr] --> src/parser.rs:244:38 [INFO] [stderr] | [INFO] [stderr] 244 | let mut file = File::open(&path).expect(&format!("Couldn't open the file at path: {:?}", path)); [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|_| panic!("Couldn't open the file at path: {:?}", path))` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::expect_fun_call)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#expect_fun_call [INFO] [stderr] [INFO] [stderr] warning: you seem to be trying to use match for destructuring a single pattern. Consider using `if let` [INFO] [stderr] --> src/parser.rs:248:5 [INFO] [stderr] | [INFO] [stderr] 248 | / match file.read_to_string(&mut s) { [INFO] [stderr] 249 | | Err(_) => panic!("couldn't read {}", display), [INFO] [stderr] 250 | | Ok(_) => (), [INFO] [stderr] 251 | | }; [INFO] [stderr] | |_____^ help: try this: `if let Err(_) = file.read_to_string(&mut s) { panic!("couldn't read {}", display) }` [INFO] [stderr] | [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match [INFO] [stderr] [INFO] [stderr] warning: Err(_) will match all errors, maybe not a good idea [INFO] [stderr] --> src/parser.rs:249:9 [INFO] [stderr] | [INFO] [stderr] 249 | Err(_) => panic!("couldn't read {}", display), [INFO] [stderr] | ^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::match_wild_err_arm)] on by default [INFO] [stderr] = note: to remove this warning, match each error separately or use unreachable macro [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_wild_err_arm [INFO] [stderr] [INFO] [stderr] warning: you should consider adding a `Default` implementation for `core::DataBase` [INFO] [stderr] --> src/core.rs:25:5 [INFO] [stderr] | [INFO] [stderr] 25 | / pub fn new() -> DataBase { [INFO] [stderr] 26 | | let db = DataBase { [INFO] [stderr] 27 | | props: HashMap::new(), [INFO] [stderr] 28 | | regions: HashMap::new(), [INFO] [stderr] ... | [INFO] [stderr] 34 | | db [INFO] [stderr] 35 | | } [INFO] [stderr] | |_____^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::new_without_default)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default [INFO] [stderr] help: try this [INFO] [stderr] | [INFO] [stderr] 24 | impl Default for core::DataBase { [INFO] [stderr] 25 | fn default() -> Self { [INFO] [stderr] 26 | Self::new() [INFO] [stderr] 27 | } [INFO] [stderr] 28 | } [INFO] [stderr] | [INFO] [stderr] [INFO] [stderr] warning: usage of `contains_key` followed by `insert` on a `HashMap` [INFO] [stderr] --> src/core.rs:38:9 [INFO] [stderr] | [INFO] [stderr] 38 | / if self.props.contains_key(&prop_addr) { [INFO] [stderr] 39 | | println!( [INFO] [stderr] 40 | | "Couldn't add prop to database because key already exists: {:?}", [INFO] [stderr] 41 | | &prop_addr [INFO] [stderr] ... | [INFO] [stderr] 44 | | self.props.insert(prop_addr, prop); [INFO] [stderr] 45 | | } [INFO] [stderr] | |_________^ help: consider using: `self.props.entry(prop_addr)` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::map_entry)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#map_entry [INFO] [stderr] [INFO] [stderr] warning: you should use the `starts_with` method [INFO] [stderr] --> src/core.rs:147:12 [INFO] [stderr] | [INFO] [stderr] 147 | if self.address.chars().next().unwrap() != '/' [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: like this: `!self.address.starts_with('/')` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::chars_next_cmp)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#chars_next_cmp [INFO] [stderr] [INFO] [stderr] warning: you should consider adding a `Default` implementation for `core::SimInstance` [INFO] [stderr] --> src/core.rs:279:5 [INFO] [stderr] | [INFO] [stderr] 279 | / pub fn new() -> SimInstance { [INFO] [stderr] 280 | | SimInstance { [INFO] [stderr] 281 | | metadata: HashMap::new(), [INFO] [stderr] 282 | | database: DataBase::new(), [INFO] [stderr] 283 | | } [INFO] [stderr] 284 | | } [INFO] [stderr] | |_____^ [INFO] [stderr] | [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#new_without_default [INFO] [stderr] help: try this [INFO] [stderr] | [INFO] [stderr] 278 | impl Default for core::SimInstance { [INFO] [stderr] 279 | fn default() -> Self { [INFO] [stderr] 280 | Self::new() [INFO] [stderr] 281 | } [INFO] [stderr] 282 | } [INFO] [stderr] | [INFO] [stderr] [INFO] [stderr] warning: called `.get().unwrap()` on a HashMap. Using `[]` is more clear and more concise [INFO] [stderr] --> src/parser.rs:81:20 [INFO] [stderr] | [INFO] [stderr] 81 | let vec = ®.hashmap.get(obj_type).unwrap(); [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `®.hashmap[obj_type]` [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: writing `&String` instead of `&str` involves a new object where a slice will do. [INFO] [stderr] --> src/parser.rs:91:15 [INFO] [stderr] | [INFO] [stderr] 91 | obj_type: &String, [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: writing `&Vec<_>` instead of `&[_]` involves one more reference and cannot be used with non-Vec-based slices. [INFO] [stderr] --> src/parser.rs:92:11 [INFO] [stderr] | [INFO] [stderr] 92 | list: &Vec, [INFO] [stderr] | ^^^^^^^^^^^^ help: change this to: `&[String]` [INFO] [stderr] | [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#ptr_arg [INFO] [stderr] [INFO] [stderr] warning: you seem to be trying to use match for destructuring a single pattern. Consider using `if let` [INFO] [stderr] --> src/parser.rs:115:5 [INFO] [stderr] | [INFO] [stderr] 115 | / match entity_type { [INFO] [stderr] 116 | | "region" => initialize_entity_region(value, world_buf), [INFO] [stderr] 117 | | _ => (), [INFO] [stderr] 118 | | } [INFO] [stderr] | |_____^ help: try this: `if let "region" = entity_type { initialize_entity_region(value, world_buf) }` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::single_match)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match [INFO] [stderr] [INFO] [stderr] warning: use of `expect` followed by a function call [INFO] [stderr] --> src/parser.rs:244:38 [INFO] [stderr] | [INFO] [stderr] 244 | let mut file = File::open(&path).expect(&format!("Couldn't open the file at path: {:?}", path)); [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: try this: `unwrap_or_else(|_| panic!("Couldn't open the file at path: {:?}", path))` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::expect_fun_call)] on by default [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#expect_fun_call [INFO] [stderr] [INFO] [stderr] warning: you seem to be trying to use match for destructuring a single pattern. Consider using `if let` [INFO] [stderr] --> src/parser.rs:248:5 [INFO] [stderr] | [INFO] [stderr] 248 | / match file.read_to_string(&mut s) { [INFO] [stderr] 249 | | Err(_) => panic!("couldn't read {}", display), [INFO] [stderr] 250 | | Ok(_) => (), [INFO] [stderr] 251 | | }; [INFO] [stderr] | |_____^ help: try this: `if let Err(_) = file.read_to_string(&mut s) { panic!("couldn't read {}", display) }` [INFO] [stderr] | [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#single_match [INFO] [stderr] [INFO] [stderr] warning: Err(_) will match all errors, maybe not a good idea [INFO] [stderr] --> src/parser.rs:249:9 [INFO] [stderr] | [INFO] [stderr] 249 | Err(_) => panic!("couldn't read {}", display), [INFO] [stderr] | ^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(clippy::match_wild_err_arm)] on by default [INFO] [stderr] = note: to remove this warning, match each error separately or use unreachable macro [INFO] [stderr] = help: for further information visit https://rust-lang.github.io/rust-clippy/master/index.html#match_wild_err_arm [INFO] [stderr] [INFO] [stderr] Finished dev [unoptimized + debuginfo] target(s) in 2.31s [INFO] running `"docker" "inspect" "72c04c502df5ced7b6f926467030e52354f71ae4b79b1ea240603c98641c906d"` [INFO] running `"docker" "rm" "-f" "72c04c502df5ced7b6f926467030e52354f71ae4b79b1ea240603c98641c906d"` [INFO] [stdout] 72c04c502df5ced7b6f926467030e52354f71ae4b79b1ea240603c98641c906d