[INFO] cloning repository https://github.com/Nov11/rust-pl
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Nov11/rust-pl" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNov11%2Frust-pl", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNov11%2Frust-pl'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0a7cf494b601889c42daf4e23e78245e01117607
[INFO] checking Nov11/rust-pl against try#45d8b6e68beee1c9c1ce92ae258a7e02f8f13aa4 for pr-83744
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNov11%2Frust-pl" "/workspace/builds/worker-2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Nov11/rust-pl 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/Nov11/rust-pl
[INFO] finished tweaking git repo https://github.com/Nov11/rust-pl
[INFO] tweaked toml for git repo https://github.com/Nov11/rust-pl written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate git repo https://github.com/Nov11/rust-pl 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded urlencoded v0.5.0
[INFO] [stderr]   Downloaded bodyparser v0.5.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] 7c61a6b6e9252714b36bca18f5b10f0630e8c9db6b1a67bff24ba7ab7dd97e00
[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" "7c61a6b6e9252714b36bca18f5b10f0630e8c9db6b1a67bff24ba7ab7dd97e00", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7c61a6b6e9252714b36bca18f5b10f0630e8c9db6b1a67bff24ba7ab7dd97e00", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7c61a6b6e9252714b36bca18f5b10f0630e8c9db6b1a67bff24ba7ab7dd97e00", kill_on_drop: false }`
[INFO] [stdout] 7c61a6b6e9252714b36bca18f5b10f0630e8c9db6b1a67bff24ba7ab7dd97e00
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] ab9a81ff6826cbafa6fcf461c17ab6ff273c837968a05f03a3e7d20f3874faa0
[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" "ab9a81ff6826cbafa6fcf461c17ab6ff273c837968a05f03a3e7d20f3874faa0", kill_on_drop: false }`
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]     Checking traitobject v0.1.0
[INFO] [stderr]     Checking smallvec v0.6.10
[INFO] [stderr]     Checking percent-encoding v1.0.1
[INFO] [stderr]     Checking typeable v0.1.2
[INFO] [stderr]     Checking language-tags v0.2.2
[INFO] [stderr]     Checking lazy_static v0.2.11
[INFO] [stderr]    Compiling rayon-core v1.6.0
[INFO] [stderr]     Checking dtoa v0.2.2
[INFO] [stderr]     Checking itoa v0.1.1
[INFO] [stderr]     Checking either v1.5.3
[INFO] [stderr]     Checking inflate v0.2.0
[INFO] [stderr]     Checking ch20 v0.1.0 (/opt/rustwide/workdir/ch20)
[INFO] [stderr]     Checking state-pattern v0.1.0 (/opt/rustwide/workdir/state-pattern)
[INFO] [stderr]     Checking crossbeam v0.2.12
[INFO] [stdout] warning: unused variable: `post`
[INFO] [stdout]   --> state-pattern/src/lib.rs:38:27
[INFO] [stdout]    |
[INFO] [stdout] 38 |     fn content<'a>(&self, post: &'a Post) -> &'a str {
[INFO] [stdout]    |                           ^^^^ help: if this is intentional, prefix it with an underscore: `_post`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking minigrep v0.1.0 (/opt/rustwide/workdir/minigrep)
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking ref-scope v0.1.0 (/opt/rustwide/workdir/ref-scope)
[INFO] [stderr]     Checking modules v0.1.0 (/opt/rustwide/workdir/modules)
[INFO] [stderr]     Checking box-usage v0.1.0 (/opt/rustwide/workdir/box-usage)
[INFO] [stderr]     Checking ch19 v0.1.0 (/opt/rustwide/workdir/ch19)
[INFO] [stderr]     Checking cmd v0.1.0 (/opt/rustwide/workdir/cmd)
[INFO] [stdout] warning: unused variable: `rhs`
[INFO] [stdout]   --> ch19/src/main.rs:18:18
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn add(self, rhs: Self) -> Self::Output {
[INFO] [stdout]    |                  ^^^ help: if this is intentional, prefix it with an underscore: `_rhs`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list`
[INFO] [stdout]  --> box-usage/src/main.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let list = List::Cons(1, Box::new(List::Nil));
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_list`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `return_fn`
[INFO] [stdout]   --> ch19/src/main.rs:23:4
[INFO] [stdout]    |
[INFO] [stdout] 23 | fn return_fn() -> Box<dyn Fn(i32) -> i32>{
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking closures v0.1.0 (/opt/rustwide/workdir/closures)
[INFO] [stderr]     Checking add_two v0.1.0 (/opt/rustwide/workdir/add_two)
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `rhs`
[INFO] [stdout]   --> ch19/src/main.rs:18:18
[INFO] [stdout]    |
[INFO] [stdout] 18 |     fn add(self, rhs: Self) -> Self::Output {
[INFO] [stdout]    |                  ^^^ help: if this is intentional, prefix it with an underscore: `_rhs`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `return_fn`
[INFO] [stdout]   --> ch19/src/main.rs:23:4
[INFO] [stdout]    |
[INFO] [stdout] 23 | fn return_fn() -> Box<dyn Fn(i32) -> i32>{
[INFO] [stdout]    |    ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling num-traits v0.2.8
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stdout] warning: unused variable: `post`
[INFO] [stdout]   --> state-pattern/src/lib.rs:38:27
[INFO] [stdout]    |
[INFO] [stdout] 38 |     fn content<'a>(&self, post: &'a Post) -> &'a str {
[INFO] [stdout]    |                           ^^^^ help: if this is intentional, prefix it with an underscore: `_post`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stdout] warning: unused variable: `v2`
[INFO] [stdout]  --> closures/src/main.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v2 = vec;
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_v2`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `plus_magic`
[INFO] [stdout]   --> closures/src/main.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let plus_magic = |x: i32| x + magic_num;
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_plus_magic`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `more_magic`
[INFO] [stdout]   --> closures/src/main.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let more_magic = &mut magic_num; // Err!
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_more_magic`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> closures/src/main.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let mut vec = vec![1, 2, 3];
[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: field is never read: `number`
[INFO] [stdout]   --> closures/src/main.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     number: i32,
[INFO] [stdout]    |     ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `default_ref`
[INFO] [stdout]   --> closures/src/main.rs:16:4
[INFO] [stdout]    |
[INFO] [stdout] 16 | fn default_ref() {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `default_move`
[INFO] [stdout]   --> closures/src/main.rs:24:4
[INFO] [stdout]    |
[INFO] [stdout] 24 | fn default_move() {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: path statement drops value
[INFO] [stdout]   --> closures/src/main.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |         numbers;
[INFO] [stdout]    |         ^^^^^^^^ help: use `drop` to clarify the intent: `drop(numbers);`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(path_statements)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `list`
[INFO] [stdout]  --> box-usage/src/main.rs:7:9
[INFO] [stdout]   |
[INFO] [stdout] 7 |     let list = List::Cons(1, Box::new(List::Nil));
[INFO] [stdout]   |         ^^^^ help: if this is intentional, prefix it with an underscore: `_list`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 8 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `v2`
[INFO] [stdout]  --> closures/src/main.rs:6:9
[INFO] [stdout]   |
[INFO] [stdout] 6 |     let v2 = vec;
[INFO] [stdout]   |         ^^ help: if this is intentional, prefix it with an underscore: `_v2`
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `plus_magic`
[INFO] [stdout]   --> closures/src/main.rs:19:9
[INFO] [stdout]    |
[INFO] [stdout] 19 |     let plus_magic = |x: i32| x + magic_num;
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_plus_magic`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `more_magic`
[INFO] [stdout]   --> closures/src/main.rs:20:9
[INFO] [stdout]    |
[INFO] [stdout] 20 |     let more_magic = &mut magic_num; // Err!
[INFO] [stdout]    |         ^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_more_magic`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> closures/src/main.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let mut vec = vec![1, 2, 3];
[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: field is never read: `number`
[INFO] [stdout]   --> closures/src/main.rs:13:5
[INFO] [stdout]    |
[INFO] [stdout] 13 |     number: i32,
[INFO] [stdout]    |     ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `default_ref`
[INFO] [stdout]   --> closures/src/main.rs:16:4
[INFO] [stdout]    |
[INFO] [stdout] 16 | fn default_ref() {
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `default_move`
[INFO] [stdout]   --> closures/src/main.rs:24:4
[INFO] [stdout]    |
[INFO] [stdout] 24 | fn default_move() {
[INFO] [stdout]    |    ^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: path statement drops value
[INFO] [stdout]   --> closures/src/main.rs:27:9
[INFO] [stdout]    |
[INFO] [stdout] 27 |         numbers;
[INFO] [stdout]    |         ^^^^^^^^ help: use `drop` to clarify the intent: `drop(numbers);`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(path_statements)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking unsafe-any v0.4.2
[INFO] [stderr]     Checking error v0.1.9
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 8 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking unicode-normalization v0.1.8
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]     Checking log v0.4.8
[INFO] [stderr]     Checking num_cpus v1.10.1
[INFO] [stderr]     Checking rand v0.5.6
[INFO] [stderr]     Checking base64 v0.9.3
[INFO] [stderr]     Checking typemap v0.3.3
[INFO] [stderr]     Checking rust-programming-language v0.1.0 (/opt/rustwide/workdir/ch01)
[INFO] [stderr]     Checking plugin v0.2.6
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]     Checking log v0.3.9
[INFO] [stderr]     Checking mime v0.2.6
[INFO] [stderr]    Compiling memoffset v0.5.1
[INFO] [stderr]     Checking idna v0.1.5
[INFO] [stderr]     Checking crossbeam-epoch v0.7.2
[INFO] [stderr]     Checking crossbeam-deque v0.7.1
[INFO] [stderr]     Checking add_one v0.1.0 (/opt/rustwide/workdir/add_one)
[INFO] [stderr]     Checking guess-game v0.1.0 (/opt/rustwide/workdir/guess-game)
[INFO] [stderr]     Checking num-traits v0.1.43
[INFO] [stderr]     Checking adder v0.1.0 (/opt/rustwide/workdir/adder)
[INFO] [stderr]     Checking serde_json v0.8.6
[INFO] [stderr]     Checking enum_primitive v0.1.1
[INFO] [stderr]     Checking url v1.7.2
[INFO] [stderr]     Checking num-iter v0.1.39
[INFO] [stderr]     Checking conduit-mime-types v0.7.3
[INFO] [stderr]     Checking num-bigint v0.1.44
[INFO] [stderr]     Checking num-complex v0.1.43
[INFO] [stderr]     Checking png v0.7.0
[INFO] [stderr]     Checking rayon v1.2.0
[INFO] [stderr]     Checking hyper v0.10.16
[INFO] [stderr]     Checking num-rational v0.1.42
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[INFO] [stderr]     Checking jpeg-decoder v0.1.16
[INFO] [stderr]     Checking iron v0.5.1
[INFO] [stderr]     Checking image v0.13.0
[INFO] [stderr]     Checking persistent v0.3.0
[INFO] [stderr]     Checking router v0.5.1
[INFO] [stderr]     Checking bodyparser v0.5.0
[INFO] [stderr]     Checking urlencoded v0.5.0
[INFO] [stderr]     Checking simple-web-server v0.1.0 (/opt/rustwide/workdir/simple-web-server)
[INFO] [stderr]     Checking concurrency v0.1.0 (/opt/rustwide/workdir/concurrency)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 25.70s
[INFO] running `Command { std: "docker" "inspect" "ab9a81ff6826cbafa6fcf461c17ab6ff273c837968a05f03a3e7d20f3874faa0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ab9a81ff6826cbafa6fcf461c17ab6ff273c837968a05f03a3e7d20f3874faa0", kill_on_drop: false }`
[INFO] [stdout] ab9a81ff6826cbafa6fcf461c17ab6ff273c837968a05f03a3e7d20f3874faa0