[INFO] cloning repository https://github.com/bookinstock/rust_example
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/bookinstock/rust_example" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbookinstock%2Frust_example", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbookinstock%2Frust_example'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c83d144f2d500cd60a59da5019b4bc5ca7d2d36f
[INFO] checking bookinstock/rust_example against try#45d8b6e68beee1c9c1ce92ae258a7e02f8f13aa4 for pr-83744
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbookinstock%2Frust_example" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/bookinstock/rust_example on toolchain 45d8b6e68beee1c9c1ce92ae258a7e02f8f13aa4
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+45d8b6e68beee1c9c1ce92ae258a7e02f8f13aa4" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/bookinstock/rust_example
[INFO] finished tweaking git repo https://github.com/bookinstock/rust_example
[INFO] tweaked toml for git repo https://github.com/bookinstock/rust_example written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/bookinstock/rust_example already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+45d8b6e68beee1c9c1ce92ae258a7e02f8f13aa4" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+45d8b6e68beee1c9c1ce92ae258a7e02f8f13aa4" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fba5a7b5e1a1b96a3c77395b47739d976aa26de09104b4c4683cf55c8176c0f4
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "fba5a7b5e1a1b96a3c77395b47739d976aa26de09104b4c4683cf55c8176c0f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fba5a7b5e1a1b96a3c77395b47739d976aa26de09104b4c4683cf55c8176c0f4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fba5a7b5e1a1b96a3c77395b47739d976aa26de09104b4c4683cf55c8176c0f4", kill_on_drop: false }`
[INFO] [stdout] fba5a7b5e1a1b96a3c77395b47739d976aa26de09104b4c4683cf55c8176c0f4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+45d8b6e68beee1c9c1ce92ae258a7e02f8f13aa4" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9d588c612af8a493a007ca3d814a4b38a9774f1ba229f55ba9aad8df92c119eb
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "9d588c612af8a493a007ca3d814a4b38a9774f1ba229f55ba9aad8df92c119eb", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_example v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0433]: failed to resolve: use of undeclared crate or module `futures`
[INFO] [stdout]   --> src/bin/async.rs:10:5
[INFO] [stdout]    |
[INFO] [stdout] 10 | use futures::executor::block_on;
[INFO] [stdout]    |     ^^^^^^^ use of undeclared crate or module `futures`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s`
[INFO] [stdout]    --> src/bin/generic.rs:217:9
[INFO] [stdout]     |
[INFO] [stdout] 217 |     let s = S(1);
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_s`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0425]: cannot find function `block_on` in this scope
[INFO] [stdout]   --> src/bin/async.rs:18:5
[INFO] [stdout]    |
[INFO] [stdout] 18 |     block_on(future); // `future` is run and "hello, world!" is printed
[INFO] [stdout]    |     ^^^^^^^^ not found in this scope
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0425, E0433.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0425`.
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `S`
[INFO] [stdout]    --> src/bin/generic.rs:135:12
[INFO] [stdout]     |
[INFO] [stdout] 135 |     struct S; // 具体类型 `S`
[INFO] [stdout]     |            ^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `GenericVal`
[INFO] [stdout]    --> src/bin/generic.rs:136:12
[INFO] [stdout]     |
[INFO] [stdout] 136 |     struct GenericVal<T>(T); // 泛型类型 `GenericVal`
[INFO] [stdout]     |            ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `printer`
[INFO] [stdout]    --> src/bin/generic.rs:210:8
[INFO] [stdout]     |
[INFO] [stdout] 210 |     fn printer<T: Display>(t: T) {
[INFO] [stdout]     |        ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_literal`
[INFO] [stdout]    --> src/bin/pattern_matching.rs:113:4
[INFO] [stdout]     |
[INFO] [stdout] 113 | fn test_literal() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_array`
[INFO] [stdout]    --> src/bin/pattern_matching.rs:115:4
[INFO] [stdout]     |
[INFO] [stdout] 115 | fn test_array() {}
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_enum`
[INFO] [stdout]    --> src/bin/pattern_matching.rs:117:4
[INFO] [stdout]     |
[INFO] [stdout] 117 | fn test_enum() {}
[INFO] [stdout]     |    ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_stuct`
[INFO] [stdout]    --> src/bin/pattern_matching.rs:119:4
[INFO] [stdout]     |
[INFO] [stdout] 119 | fn test_stuct() {}
[INFO] [stdout]     |    ^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_variable`
[INFO] [stdout]    --> src/bin/pattern_matching.rs:137:4
[INFO] [stdout]     |
[INFO] [stdout] 137 | fn test_variable() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_wildcard`
[INFO] [stdout]    --> src/bin/pattern_matching.rs:139:4
[INFO] [stdout]     |
[INFO] [stdout] 139 | fn test_wildcard() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `test_placeholder`
[INFO] [stdout]    --> src/bin/pattern_matching.rs:141:4
[INFO] [stdout]     |
[INFO] [stdout] 141 | fn test_placeholder() {}
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Nil`
[INFO] [stdout]   --> src/bin/custom_type.rs:30:8
[INFO] [stdout]    |
[INFO] [stdout] 30 | struct Nil;
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_example`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Nil`
[INFO] [stdout]   --> src/bin/custom_type.rs:30:8
[INFO] [stdout]    |
[INFO] [stdout] 30 | struct Nil;
[INFO] [stdout]    |        ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Rich`
[INFO] [stdout]    --> src/bin/custom_type.rs:117:9
[INFO] [stdout]     |
[INFO] [stdout] 117 |         Rich,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Soldier`
[INFO] [stdout]    --> src/bin/custom_type.rs:123:9
[INFO] [stdout]     |
[INFO] [stdout] 123 |         Soldier,
[INFO] [stdout]     |         ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/scope.rs:88:9
[INFO] [stdout]    |
[INFO] [stdout] 88 |     let x = ToDrop;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ref_x`
[INFO] [stdout]    --> src/bin/scope.rs:401:13
[INFO] [stdout]     |
[INFO] [stdout] 401 |         let ref_x = &x;
[INFO] [stdout]     |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_ref_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/scope.rs:405:13
[INFO] [stdout]     |
[INFO] [stdout] 405 |         let mut ref_x = &mut x;
[INFO] [stdout]     |             ----^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `ps_ref`
[INFO] [stdout]    --> src/bin/scope.rs:444:4
[INFO] [stdout]     |
[INFO] [stdout] 444 | fn ps_ref() {
[INFO] [stdout]     |    ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/bin/scope.rs:88:9
[INFO] [stdout]    |
[INFO] [stdout] 88 |     let x = ToDrop;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `ref_x`
[INFO] [stdout]    --> src/bin/scope.rs:401:13
[INFO] [stdout]     |
[INFO] [stdout] 401 |         let ref_x = &x;
[INFO] [stdout]     |             ^^^^^ help: if this is intentional, prefix it with an underscore: `_ref_x`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/bin/scope.rs:405:13
[INFO] [stdout]     |
[INFO] [stdout] 405 |         let mut ref_x = &mut x;
[INFO] [stdout]     |             ----^^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `ps_ref`
[INFO] [stdout]    --> src/bin/scope.rs:444:4
[INFO] [stdout]     |
[INFO] [stdout] 444 | fn ps_ref() {
[INFO] [stdout]     |    ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused label
[INFO] [stdout]    --> src/bin/control_flow.rs:119:9
[INFO] [stdout]     |
[INFO] [stdout] 119 |         'inner: loop {
[INFO] [stdout]     |         ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_labels)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unreachable statement
[INFO] [stdout]    --> src/bin/control_flow.rs:125:9
[INFO] [stdout]     |
[INFO] [stdout] 122 |             break 'outer;
[INFO] [stdout]     |             ------------ any code following this expression is unreachable
[INFO] [stdout] ...
[INFO] [stdout] 125 |         println!("never reach");
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^ unreachable statement
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unreachable_code)]` on by default
[INFO] [stdout]     = note: this warning originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `noisy_unused_variable`
[INFO] [stdout]   --> src/bin/var_binding.rs:26:9
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let noisy_unused_variable = 2u32;
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_noisy_unused_variable`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Red`
[INFO] [stdout]    --> src/bin/control_flow.rs:247:9
[INFO] [stdout]     |
[INFO] [stdout] 247 |         Red,
[INFO] [stdout]     |         ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Blue`
[INFO] [stdout]    --> src/bin/control_flow.rs:248:9
[INFO] [stdout]     |
[INFO] [stdout] 248 |         Blue,
[INFO] [stdout]     |         ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `Green`
[INFO] [stdout]    --> src/bin/control_flow.rs:249:9
[INFO] [stdout]     |
[INFO] [stdout] 249 |         Green,
[INFO] [stdout]     |         ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `HSV`
[INFO] [stdout]    --> src/bin/control_flow.rs:251:9
[INFO] [stdout]     |
[INFO] [stdout] 251 |         HSV(u32, u32, u32),
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `HSL`
[INFO] [stdout]    --> src/bin/control_flow.rs:252:9
[INFO] [stdout]     |
[INFO] [stdout] 252 |         HSL(u32, u32, u32),
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `CMY`
[INFO] [stdout]    --> src/bin/control_flow.rs:253:9
[INFO] [stdout]     |
[INFO] [stdout] 253 |         CMY(u32, u32, u32),
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `CMYK`
[INFO] [stdout]    --> src/bin/control_flow.rs:254:9
[INFO] [stdout]     |
[INFO] [stdout] 254 |         CMYK(u32, u32, u32, u32),
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `vec2`
[INFO] [stdout]    --> src/bin/function.rs:391:9
[INFO] [stdout]     |
[INFO] [stdout] 391 |     let vec2 = vec![4, 5, 6];
[INFO] [stdout]     |         ^^^^ help: if this is intentional, prefix it with an underscore: `_vec2`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 9 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: this method call currently resolves to `<&[T; N] as IntoIterator>::into_iter` (due to autoref coercions), but that might change in the future when `IntoIterator` impls for arrays are added.
[INFO] [stdout]    --> src/bin/function.rs:431:16
[INFO] [stdout]     |
[INFO] [stdout] 431 |         array2.into_iter().find(|&&x| x == 2)
[INFO] [stdout]     |                ^^^^^^^^^ help: use `.iter()` instead of `.into_iter()` to avoid ambiguity: `iter`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(array_into_iter)]` on by default
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in a future release!
[INFO] [stdout]     = note: for more information, see issue #66145 <https://github.com/rust-lang/rust/issues/66145>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "9d588c612af8a493a007ca3d814a4b38a9774f1ba229f55ba9aad8df92c119eb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9d588c612af8a493a007ca3d814a4b38a9774f1ba229f55ba9aad8df92c119eb", kill_on_drop: false }`
[INFO] [stdout] 9d588c612af8a493a007ca3d814a4b38a9774f1ba229f55ba9aad8df92c119eb