[INFO] fetching crate unit15 0.1.0...
[INFO] testing unit15-0.1.0 against 1.100.0-beta.1 for beta-1.100-2
[INFO] extracting crate unit15 0.1.0 into /workspace/builds/worker-7-tc2/source
[INFO] started tweaking crates.io crate unit15 0.1.0
[INFO] finished tweaking crates.io crate unit15 0.1.0
[INFO] tweaked toml for crates.io crate unit15 0.1.0 written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate unit15 0.1.0 on toolchain 1.100.0-beta.1
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.100.0-beta.1" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate unit15 0.1.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.100.0-beta.1" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:3111399a4047eeb3a02b7a90e478d715f38a8c6669b5c4b49d30a17385265909" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3
[INFO] running `Command { std: "docker" "start" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3" "/opt/rustwide/cargo-home/bin/cargo" "+1.100.0-beta.1" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-w" "/opt/rustwide/workdir" "--user" "0:0" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3" "/opt/rustwide/cargo-home/bin/cargo" "+1.100.0-beta.1" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr]    Compiling unit15 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/main.rs:220:9
[INFO] [stdout]     |
[INFO] [stdout] 220 |     let a = Cons(1, Rc::clone(&rc_list));// 调用Rc::clone(&rc_list)，此处变量rc_list的引用计数为1
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]    --> src/main.rs:223:13
[INFO] [stdout]     |
[INFO] [stdout] 223 |         let b = Cons(0, Rc::clone(&rc_list));// 调用Rc::clone(&rc_list)，此处变量rc_list的引用计数为2
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `value` and `children` are never read
[INFO] [stdout]   --> src/main.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 58 |     struct Node {
[INFO] [stdout]    |            ---- fields in this struct
[INFO] [stdout] 59 |         value: i32,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 60 |         parent: RefCell<Weak<Node>>,
[INFO] [stdout] 61 |         children: RefCell<Vec<Rc<Node>>>,
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/main.rs:89:14
[INFO] [stdout]    |
[INFO] [stdout] 89 |         Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout]    |         ---- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 89 -         Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout] 89 +         Cons((), RefCell<Rc<List>>),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]    --> src/main.rs:117:14
[INFO] [stdout]     |
[INFO] [stdout] 117 |         Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout]     |         ---- ^^^^^^^^^^^^^^^^  ^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         fields in this variant
[INFO] [stdout]     |
[INFO] [stdout]     = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]     |
[INFO] [stdout] 117 -         Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout] 117 +         Cons((), ()),
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `rc_smart_pointer` is never used
[INFO] [stdout]    --> src/main.rs:214:4
[INFO] [stdout]     |
[INFO] [stdout] 214 | fn rc_smart_pointer() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `1` is never read
[INFO] [stdout]    --> src/main.rs:287:13
[INFO] [stdout]     |
[INFO] [stdout] 287 |     Cons(T, Box<List<T>>),
[INFO] [stdout]     |     ----    ^^^^^^^^^^^^
[INFO] [stdout]     |     |
[INFO] [stdout]     |     field in this variant
[INFO] [stdout]     |
[INFO] [stdout]     = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]     |
[INFO] [stdout] 287 -     Cons(T, Box<List<T>>),
[INFO] [stdout] 287 +     Cons(T, ()),
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `RcList` is never used
[INFO] [stdout]    --> src/main.rs:292:6
[INFO] [stdout]     |
[INFO] [stdout] 292 | enum RcList<T> {
[INFO] [stdout]     |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.29s
[INFO] running `Command { std: "docker" "inspect" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-w" "/opt/rustwide/workdir" "--user" "0:0" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3" "/opt/rustwide/cargo-home/bin/cargo" "+1.100.0-beta.1" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr]    Compiling unit15 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/main.rs:220:9
[INFO] [stdout]     |
[INFO] [stdout] 220 |     let a = Cons(1, Rc::clone(&rc_list));// 调用Rc::clone(&rc_list)，此处变量rc_list的引用计数为1
[INFO] [stdout]     |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]    --> src/main.rs:223:13
[INFO] [stdout]     |
[INFO] [stdout] 223 |         let b = Cons(0, Rc::clone(&rc_list));// 调用Rc::clone(&rc_list)，此处变量rc_list的引用计数为2
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `value` and `children` are never read
[INFO] [stdout]   --> src/main.rs:59:9
[INFO] [stdout]    |
[INFO] [stdout] 58 |     struct Node {
[INFO] [stdout]    |            ---- fields in this struct
[INFO] [stdout] 59 |         value: i32,
[INFO] [stdout]    |         ^^^^^
[INFO] [stdout] 60 |         parent: RefCell<Weak<Node>>,
[INFO] [stdout] 61 |         children: RefCell<Vec<Rc<Node>>>,
[INFO] [stdout]    |         ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]   --> src/main.rs:89:14
[INFO] [stdout]    |
[INFO] [stdout] 89 |         Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout]    |         ---- ^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         field in this variant
[INFO] [stdout]    |
[INFO] [stdout]    = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]    |
[INFO] [stdout] 89 -         Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout] 89 +         Cons((), RefCell<Rc<List>>),
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]    --> src/main.rs:117:14
[INFO] [stdout]     |
[INFO] [stdout] 117 |         Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout]     |         ---- ^^^^^^^^^^^^^^^^  ^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         fields in this variant
[INFO] [stdout]     |
[INFO] [stdout]     = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]     |
[INFO] [stdout] 117 -         Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout] 117 +         Cons((), ()),
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `rc_smart_pointer` is never used
[INFO] [stdout]    --> src/main.rs:214:4
[INFO] [stdout]     |
[INFO] [stdout] 214 | fn rc_smart_pointer() {
[INFO] [stdout]     |    ^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: field `1` is never read
[INFO] [stdout]    --> src/main.rs:287:13
[INFO] [stdout]     |
[INFO] [stdout] 287 |     Cons(T, Box<List<T>>),
[INFO] [stdout]     |     ----    ^^^^^^^^^^^^
[INFO] [stdout]     |     |
[INFO] [stdout]     |     field in this variant
[INFO] [stdout]     |
[INFO] [stdout]     = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]     |
[INFO] [stdout] 287 -     Cons(T, Box<List<T>>),
[INFO] [stdout] 287 +     Cons(T, ()),
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum `RcList` is never used
[INFO] [stdout]    --> src/main.rs:292:6
[INFO] [stdout]     |
[INFO] [stdout] 292 | enum RcList<T> {
[INFO] [stdout]     |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.18s
[INFO] running `Command { std: "docker" "inspect" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-w" "/opt/rustwide/workdir" "--user" "0:0" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3" "/opt/rustwide/cargo-home/bin/cargo" "+1.100.0-beta.1" "test" "--frozen", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `a`
[INFO] [stderr]    --> src/main.rs:220:9
[INFO] [stderr]     |
[INFO] [stderr] 220 |     let a = Cons(1, Rc::clone(&rc_list));// 调用Rc::clone(&rc_list)，此处变量rc_list的引用计数为1
[INFO] [stderr]     |         ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_variables)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]    --> src/main.rs:223:13
[INFO] [stderr]     |
[INFO] [stderr] 223 |         let b = Cons(0, Rc::clone(&rc_list));// 调用Rc::clone(&rc_list)，此处变量rc_list的引用计数为2
[INFO] [stderr]     |             ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: fields `value` and `children` are never read
[INFO] [stderr]   --> src/main.rs:59:9
[INFO] [stderr]    |
[INFO] [stderr] 58 |     struct Node {
[INFO] [stderr]    |            ---- fields in this struct
[INFO] [stderr] 59 |         value: i32,
[INFO] [stderr]    |         ^^^^^
[INFO] [stderr] 60 |         parent: RefCell<Weak<Node>>,
[INFO] [stderr] 61 |         children: RefCell<Vec<Rc<Node>>>,
[INFO] [stderr]    |         ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `Node` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stderr]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stderr] 
[INFO] [stderr] warning: field `0` is never read
[INFO] [stderr]   --> src/main.rs:89:14
[INFO] [stderr]    |
[INFO] [stderr] 89 |         Cons(i32, RefCell<Rc<List>>),
[INFO] [stderr]    |         ---- ^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         field in this variant
[INFO] [stderr]    |
[INFO] [stderr]    = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stderr] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stderr]    |
[INFO] [stderr] 89 -         Cons(i32, RefCell<Rc<List>>),
[INFO] [stderr] 89 +         Cons((), RefCell<Rc<List>>),
[INFO] [stderr]    |
[INFO] [stderr] 
[INFO] [stderr] warning: fields `0` and `1` are never read
[INFO] [stderr]    --> src/main.rs:117:14
[INFO] [stderr]     |
[INFO] [stderr] 117 |         Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stderr]     |         ---- ^^^^^^^^^^^^^^^^  ^^^^^^^^
[INFO] [stderr]     |         |
[INFO] [stderr]     |         fields in this variant
[INFO] [stderr]     |
[INFO] [stderr]     = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stderr] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stderr]     |
[INFO] [stderr] 117 -         Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stderr] 117 +         Cons((), ()),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: function `rc_smart_pointer` is never used
[INFO] [stderr]    --> src/main.rs:214:4
[INFO] [stderr]     |
[INFO] [stderr] 214 | fn rc_smart_pointer() {
[INFO] [stderr]     |    ^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: field `1` is never read
[INFO] [stderr]    --> src/main.rs:287:13
[INFO] [stderr]     |
[INFO] [stderr] 287 |     Cons(T, Box<List<T>>),
[INFO] [stderr]     |     ----    ^^^^^^^^^^^^
[INFO] [stderr]     |     |
[INFO] [stderr]     |     field in this variant
[INFO] [stderr]     |
[INFO] [stderr]     = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stderr] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stderr]     |
[INFO] [stderr] 287 -     Cons(T, Box<List<T>>),
[INFO] [stderr] 287 +     Cons(T, ()),
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] warning: enum `RcList` is never used
[INFO] [stderr]    --> src/main.rs:292:6
[INFO] [stderr]     |
[INFO] [stderr] 292 | enum RcList<T> {
[INFO] [stderr]     |      ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: `unit15` (bin "unit15" test) generated 8 warnings (run `cargo fix --bin "unit15" -p unit15 --tests` to apply 2 suggestions)
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running unittests src/main.rs (/opt/rustwide/target/debug/build/unit15/75aae417efbb21f1/out/unit15-75aae417efbb21f1)
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3", kill_on_drop: false }`
[INFO] [stdout] fdc9807aae6a69b6a600550556e870e1852df8ec5af1d172ca234296ba48b5a3
