[INFO] updating cached repository lucke84/playing_around_with_rust [INFO] running `"git" "fetch" "--all"` [INFO] [stdout] Fetching origin [INFO] [stderr] From git://github.com/lucke84/playing_around_with_rust [INFO] [stderr] * branch HEAD -> FETCH_HEAD [INFO] running `"git" "clone" "work/cache/sources/gh/lucke84/playing_around_with_rust" "work/ex/pr-59199/sources/master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7/gh/lucke84/playing_around_with_rust"` [INFO] [stderr] Cloning into 'work/ex/pr-59199/sources/master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7/gh/lucke84/playing_around_with_rust'... [INFO] [stderr] done. [INFO] running `"git" "clone" "work/cache/sources/gh/lucke84/playing_around_with_rust" "work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/gh/lucke84/playing_around_with_rust"` [INFO] [stderr] Cloning into 'work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/gh/lucke84/playing_around_with_rust'... [INFO] [stderr] done. [INFO] running `"git" "rev-parse" "HEAD"` [INFO] [stdout] 258cf4006127f9f86cf750b991e2051b64bf8a08 [INFO] sha for GitHub repo lucke84/playing_around_with_rust: 258cf4006127f9f86cf750b991e2051b64bf8a08 [INFO] validating manifest of lucke84/playing_around_with_rust 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 lucke84/playing_around_with_rust 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 lucke84/playing_around_with_rust [INFO] finished frobbing lucke84/playing_around_with_rust [INFO] frobbed toml for lucke84/playing_around_with_rust written to work/ex/pr-59199/sources/master#bc44841ad2a2ad5f6c5e67b9e35ed8e7e71d4dc7/gh/lucke84/playing_around_with_rust/Cargo.toml [INFO] started frobbing lucke84/playing_around_with_rust [INFO] finished frobbing lucke84/playing_around_with_rust [INFO] frobbed toml for lucke84/playing_around_with_rust written to work/ex/pr-59199/sources/try#68fcf881bd1e4dbfc21e22f8c7a56b8a5d8e8f7b/gh/lucke84/playing_around_with_rust/Cargo.toml [INFO] crate lucke84/playing_around_with_rust already has a lockfile, it will not be regenerated [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 lucke84/playing_around_with_rust 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/gh/lucke84/playing_around_with_rust:/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] cec05e8add043cfcf740b0fe1a74e76347b993519df7416a30f646d869e56098 [INFO] running `"docker" "start" "-a" "cec05e8add043cfcf740b0fe1a74e76347b993519df7416a30f646d869e56098"` [INFO] [stderr] Checking playing_around_with_rust v0.0.1 (/opt/crater/workdir) [INFO] [stderr] warning: unnecessary parentheses around assigned value [INFO] [stderr] --> src/main.rs:37:13 [INFO] [stderr] | [INFO] [stderr] 37 | let j = (i = 6); // the value of an assignment is an empty tuple: so j has the value (), not 6 [INFO] [stderr] | ^^^^^^^ help: remove these parentheses [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_parens)] on by default [INFO] [stderr] [INFO] [stderr] warning: unreachable expression [INFO] [stderr] --> src/main.rs:137:5 [INFO] [stderr] | [INFO] [stderr] 137 | x // never executed [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unreachable_code)] on by default [INFO] [stderr] [INFO] [stderr] warning: unused variable: `a` [INFO] [stderr] --> src/main.rs:7:9 [INFO] [stderr] | [INFO] [stderr] 7 | let a = 1; // type i32 is infered [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_a` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_variables)] on by default [INFO] [stderr] [INFO] [stderr] warning: unused variable: `b` [INFO] [stderr] --> src/main.rs:8:9 [INFO] [stderr] | [INFO] [stderr] 8 | let b: i32 = 2; // type i32 is explicitly declared [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_b` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `c` [INFO] [stderr] --> src/main.rs:10:10 [INFO] [stderr] | [INFO] [stderr] 10 | let (c, d) = (3, 4); // variable bindings of multiple vars at the same time [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_c` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `d` [INFO] [stderr] --> src/main.rs:10:13 [INFO] [stderr] | [INFO] [stderr] 10 | let (c, d) = (3, 4); // variable bindings of multiple vars at the same time [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_d` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `e` [INFO] [stderr] --> src/main.rs:12:9 [INFO] [stderr] | [INFO] [stderr] 12 | let e: i32; [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_e` [INFO] [stderr] [INFO] [stderr] warning: variable `f` is assigned to, but never used [INFO] [stderr] --> src/main.rs:18:13 [INFO] [stderr] | [INFO] [stderr] 18 | let mut f = 5; // make variable mutable [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = note: consider using `_f` instead [INFO] [stderr] [INFO] [stderr] warning: value assigned to `f` is never read [INFO] [stderr] --> src/main.rs:19:5 [INFO] [stderr] | [INFO] [stderr] 19 | f = 6; // now I can assign a new value (of the same type!) to this variable [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_assignments)] on by default [INFO] [stderr] = help: maybe it is overwritten before being read? [INFO] [stderr] [INFO] [stderr] warning: unused variable: `f` [INFO] [stderr] --> src/main.rs:20:9 [INFO] [stderr] | [INFO] [stderr] 20 | let f = "Look, I am text now"; // shadowing, and changing type! [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_f` [INFO] [stderr] [INFO] [stderr] warning: value assigned to `i` is never read [INFO] [stderr] --> src/main.rs:36:13 [INFO] [stderr] | [INFO] [stderr] 36 | let mut i = 5; [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = help: maybe it is overwritten before being read? [INFO] [stderr] [INFO] [stderr] warning: unused variable: `j` [INFO] [stderr] --> src/main.rs:37:9 [INFO] [stderr] | [INFO] [stderr] 37 | let j = (i = 6); // the value of an assignment is an empty tuple: so j has the value (), not 6 [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_j` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `a_boolean` [INFO] [stderr] --> src/main.rs:59:9 [INFO] [stderr] | [INFO] [stderr] 59 | let a_boolean = true; // with inference [INFO] [stderr] | ^^^^^^^^^ help: consider prefixing with an underscore: `_a_boolean` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `another_boolean` [INFO] [stderr] --> src/main.rs:60:9 [INFO] [stderr] | [INFO] [stderr] 60 | let another_boolean: bool = false; // without inference [INFO] [stderr] | ^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_another_boolean` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `this_is_a_char` [INFO] [stderr] --> src/main.rs:63:9 [INFO] [stderr] | [INFO] [stderr] 63 | let this_is_a_char = 'x'; // delimited by a single quote/tick [INFO] [stderr] | ^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_this_is_a_char` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `two_hearts_char` [INFO] [stderr] --> src/main.rs:64:9 [INFO] [stderr] | [INFO] [stderr] 64 | let two_hearts_char = '💕'; // any unicode char (due to the fact that they are UTF-32, all chars are 4 bytes instead of just 1) [INFO] [stderr] | ^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_two_hearts_char` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `an_integer` [INFO] [stderr] --> src/main.rs:67:9 [INFO] [stderr] | [INFO] [stderr] 67 | let an_integer = 42; // default with inference (type i32 - The 32-bit signed integer type) [INFO] [stderr] | ^^^^^^^^^^ help: consider prefixing with an underscore: `_an_integer` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `a_float` [INFO] [stderr] --> src/main.rs:68:9 [INFO] [stderr] | [INFO] [stderr] 68 | let a_float = 1.0; // default with inference (type f64 - The 64-bit floating point type) [INFO] [stderr] | ^^^^^^^ help: consider prefixing with an underscore: `_a_float` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `complete_slice` [INFO] [stderr] --> src/main.rs:99:9 [INFO] [stderr] | [INFO] [stderr] 99 | let complete_slice = &mutable_array[..]; // [5, 7, 3, 23, 11] [INFO] [stderr] | ^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_complete_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `partial_slice` [INFO] [stderr] --> src/main.rs:100:9 [INFO] [stderr] | [INFO] [stderr] 100 | let partial_slice = &mutable_array[1..3]; // [7, 4] - from item at index 1 to item at index 3 (excluded) [INFO] [stderr] | ^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_partial_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `from_item_till_end_slice` [INFO] [stderr] --> src/main.rs:101:9 [INFO] [stderr] | [INFO] [stderr] 101 | let from_item_till_end_slice = &mutable_array[1..]; // [7, 4, 23, 11] [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_from_item_till_end_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `from_beginning_till_item_slice` [INFO] [stderr] --> src/main.rs:102:9 [INFO] [stderr] | [INFO] [stderr] 102 | let from_beginning_till_item_slice = &mutable_array[..2]; // [5, 7] [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_from_beginning_till_item_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `tuple_one` [INFO] [stderr] --> src/main.rs:106:9 [INFO] [stderr] | [INFO] [stderr] 106 | let tuple_one = (1, "one"); [INFO] [stderr] | ^^^^^^^^^ help: consider prefixing with an underscore: `_tuple_one` [INFO] [stderr] [INFO] [stderr] warning: value assigned to `tuple_xy` is never read [INFO] [stderr] --> src/main.rs:110:13 [INFO] [stderr] | [INFO] [stderr] 110 | let mut tuple_xy = (0, "zero"); [INFO] [stderr] | ^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = help: maybe it is overwritten before being read? [INFO] [stderr] [INFO] [stderr] warning: unused variable: `tuple_second_item` [INFO] [stderr] --> src/main.rs:123:9 [INFO] [stderr] | [INFO] [stderr] 123 | let tuple_second_item = tuple_xy.1; [INFO] [stderr] | ^^^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_tuple_second_item` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `x` [INFO] [stderr] --> src/main.rs:135:22 [INFO] [stderr] | [INFO] [stderr] 135 | fn always_return_one(x: i32) -> i32 { [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_x` [INFO] [stderr] [INFO] [stderr] warning: variable does not need to be mutable [INFO] [stderr] --> src/main.rs:87:9 [INFO] [stderr] | [INFO] [stderr] 87 | let mut mutable_array = [1.5, 2.3, 3.0]; // type [f64; 3] [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: function is never used: `diverges` [INFO] [stderr] --> src/main.rs:140:1 [INFO] [stderr] | [INFO] [stderr] 140 | fn diverges() -> ! { // defines the return type as "diverges" using the bang symbol [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(dead_code)] on by default [INFO] [stderr] [INFO] [stderr] warning: unnecessary parentheses around assigned value [INFO] [stderr] --> src/main.rs:37:13 [INFO] [stderr] | [INFO] [stderr] 37 | let j = (i = 6); // the value of an assignment is an empty tuple: so j has the value (), not 6 [INFO] [stderr] | ^^^^^^^ help: remove these parentheses [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_parens)] on by default [INFO] [stderr] [INFO] [stderr] warning: unreachable expression [INFO] [stderr] --> src/main.rs:137:5 [INFO] [stderr] | [INFO] [stderr] 137 | x // never executed [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unreachable_code)] on by default [INFO] [stderr] [INFO] [stderr] warning: unused variable: `a` [INFO] [stderr] --> src/main.rs:7:9 [INFO] [stderr] | [INFO] [stderr] 7 | let a = 1; // type i32 is infered [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_a` [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_variables)] on by default [INFO] [stderr] [INFO] [stderr] warning: unused variable: `b` [INFO] [stderr] --> src/main.rs:8:9 [INFO] [stderr] | [INFO] [stderr] 8 | let b: i32 = 2; // type i32 is explicitly declared [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_b` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `c` [INFO] [stderr] --> src/main.rs:10:10 [INFO] [stderr] | [INFO] [stderr] 10 | let (c, d) = (3, 4); // variable bindings of multiple vars at the same time [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_c` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `d` [INFO] [stderr] --> src/main.rs:10:13 [INFO] [stderr] | [INFO] [stderr] 10 | let (c, d) = (3, 4); // variable bindings of multiple vars at the same time [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_d` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `e` [INFO] [stderr] --> src/main.rs:12:9 [INFO] [stderr] | [INFO] [stderr] 12 | let e: i32; [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_e` [INFO] [stderr] [INFO] [stderr] warning: variable `f` is assigned to, but never used [INFO] [stderr] --> src/main.rs:18:13 [INFO] [stderr] | [INFO] [stderr] 18 | let mut f = 5; // make variable mutable [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = note: consider using `_f` instead [INFO] [stderr] [INFO] [stderr] warning: value assigned to `f` is never read [INFO] [stderr] --> src/main.rs:19:5 [INFO] [stderr] | [INFO] [stderr] 19 | f = 6; // now I can assign a new value (of the same type!) to this variable [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(unused_assignments)] on by default [INFO] [stderr] = help: maybe it is overwritten before being read? [INFO] [stderr] [INFO] [stderr] warning: unused variable: `f` [INFO] [stderr] --> src/main.rs:20:9 [INFO] [stderr] | [INFO] [stderr] 20 | let f = "Look, I am text now"; // shadowing, and changing type! [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_f` [INFO] [stderr] [INFO] [stderr] warning: value assigned to `i` is never read [INFO] [stderr] --> src/main.rs:36:13 [INFO] [stderr] | [INFO] [stderr] 36 | let mut i = 5; [INFO] [stderr] | ^ [INFO] [stderr] | [INFO] [stderr] = help: maybe it is overwritten before being read? [INFO] [stderr] [INFO] [stderr] warning: unused variable: `j` [INFO] [stderr] --> src/main.rs:37:9 [INFO] [stderr] | [INFO] [stderr] 37 | let j = (i = 6); // the value of an assignment is an empty tuple: so j has the value (), not 6 [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_j` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `a_boolean` [INFO] [stderr] --> src/main.rs:59:9 [INFO] [stderr] | [INFO] [stderr] 59 | let a_boolean = true; // with inference [INFO] [stderr] | ^^^^^^^^^ help: consider prefixing with an underscore: `_a_boolean` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `another_boolean` [INFO] [stderr] --> src/main.rs:60:9 [INFO] [stderr] | [INFO] [stderr] 60 | let another_boolean: bool = false; // without inference [INFO] [stderr] | ^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_another_boolean` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `this_is_a_char` [INFO] [stderr] --> src/main.rs:63:9 [INFO] [stderr] | [INFO] [stderr] 63 | let this_is_a_char = 'x'; // delimited by a single quote/tick [INFO] [stderr] | ^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_this_is_a_char` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `two_hearts_char` [INFO] [stderr] --> src/main.rs:64:9 [INFO] [stderr] | [INFO] [stderr] 64 | let two_hearts_char = '💕'; // any unicode char (due to the fact that they are UTF-32, all chars are 4 bytes instead of just 1) [INFO] [stderr] | ^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_two_hearts_char` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `an_integer` [INFO] [stderr] --> src/main.rs:67:9 [INFO] [stderr] | [INFO] [stderr] 67 | let an_integer = 42; // default with inference (type i32 - The 32-bit signed integer type) [INFO] [stderr] | ^^^^^^^^^^ help: consider prefixing with an underscore: `_an_integer` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `a_float` [INFO] [stderr] --> src/main.rs:68:9 [INFO] [stderr] | [INFO] [stderr] 68 | let a_float = 1.0; // default with inference (type f64 - The 64-bit floating point type) [INFO] [stderr] | ^^^^^^^ help: consider prefixing with an underscore: `_a_float` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `complete_slice` [INFO] [stderr] --> src/main.rs:99:9 [INFO] [stderr] | [INFO] [stderr] 99 | let complete_slice = &mutable_array[..]; // [5, 7, 3, 23, 11] [INFO] [stderr] | ^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_complete_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `partial_slice` [INFO] [stderr] --> src/main.rs:100:9 [INFO] [stderr] | [INFO] [stderr] 100 | let partial_slice = &mutable_array[1..3]; // [7, 4] - from item at index 1 to item at index 3 (excluded) [INFO] [stderr] | ^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_partial_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `from_item_till_end_slice` [INFO] [stderr] --> src/main.rs:101:9 [INFO] [stderr] | [INFO] [stderr] 101 | let from_item_till_end_slice = &mutable_array[1..]; // [7, 4, 23, 11] [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_from_item_till_end_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `from_beginning_till_item_slice` [INFO] [stderr] --> src/main.rs:102:9 [INFO] [stderr] | [INFO] [stderr] 102 | let from_beginning_till_item_slice = &mutable_array[..2]; // [5, 7] [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_from_beginning_till_item_slice` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `tuple_one` [INFO] [stderr] --> src/main.rs:106:9 [INFO] [stderr] | [INFO] [stderr] 106 | let tuple_one = (1, "one"); [INFO] [stderr] | ^^^^^^^^^ help: consider prefixing with an underscore: `_tuple_one` [INFO] [stderr] [INFO] [stderr] warning: value assigned to `tuple_xy` is never read [INFO] [stderr] --> src/main.rs:110:13 [INFO] [stderr] | [INFO] [stderr] 110 | let mut tuple_xy = (0, "zero"); [INFO] [stderr] | ^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = help: maybe it is overwritten before being read? [INFO] [stderr] [INFO] [stderr] warning: unused variable: `tuple_second_item` [INFO] [stderr] --> src/main.rs:123:9 [INFO] [stderr] | [INFO] [stderr] 123 | let tuple_second_item = tuple_xy.1; [INFO] [stderr] | ^^^^^^^^^^^^^^^^^ help: consider prefixing with an underscore: `_tuple_second_item` [INFO] [stderr] [INFO] [stderr] warning: unused variable: `x` [INFO] [stderr] --> src/main.rs:135:22 [INFO] [stderr] | [INFO] [stderr] 135 | fn always_return_one(x: i32) -> i32 { [INFO] [stderr] | ^ help: consider prefixing with an underscore: `_x` [INFO] [stderr] [INFO] [stderr] warning: variable does not need to be mutable [INFO] [stderr] --> src/main.rs:87:9 [INFO] [stderr] | [INFO] [stderr] 87 | let mut mutable_array = [1.5, 2.3, 3.0]; // type [f64; 3] [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: function is never used: `diverges` [INFO] [stderr] --> src/main.rs:140:1 [INFO] [stderr] | [INFO] [stderr] 140 | fn diverges() -> ! { // defines the return type as "diverges" using the bang symbol [INFO] [stderr] | ^^^^^^^^^^^^^^^^^^ [INFO] [stderr] | [INFO] [stderr] = note: #[warn(dead_code)] on by default [INFO] [stderr] [INFO] [stderr] Finished dev [unoptimized + debuginfo] target(s) in 0.28s [INFO] running `"docker" "inspect" "cec05e8add043cfcf740b0fe1a74e76347b993519df7416a30f646d869e56098"` [INFO] running `"docker" "rm" "-f" "cec05e8add043cfcf740b0fe1a74e76347b993519df7416a30f646d869e56098"` [INFO] [stdout] cec05e8add043cfcf740b0fe1a74e76347b993519df7416a30f646d869e56098