[INFO] cloning repository https://github.com/EdenCao/rust_learning
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/EdenCao/rust_learning" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEdenCao%2Frust_learning", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEdenCao%2Frust_learning'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3b85aa524f292dd7b9939ed7d5de8b6456618f9f
[INFO] checking EdenCao/rust_learning against master#af4a5a13a15fa0c60e06321077ef452f769b42fd for pr-122960-3
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FEdenCao%2Frust_learning" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/EdenCao/rust_learning on toolchain af4a5a13a15fa0c60e06321077ef452f769b42fd
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/EdenCao/rust_learning
[INFO] finished tweaking git repo https://github.com/EdenCao/rust_learning
[INFO] tweaked toml for git repo https://github.com/EdenCao/rust_learning written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/EdenCao/rust_learning 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" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8073b914737e52480125304e9fa98528353e8797ded0c9136a4d421061e9f0ad
[INFO] running `Command { std: "docker" "start" "-a" "8073b914737e52480125304e9fa98528353e8797ded0c9136a4d421061e9f0ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8073b914737e52480125304e9fa98528353e8797ded0c9136a4d421061e9f0ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8073b914737e52480125304e9fa98528353e8797ded0c9136a4d421061e9f0ad", kill_on_drop: false }`
[INFO] [stdout] 8073b914737e52480125304e9fa98528353e8797ded0c9136a4d421061e9f0ad
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+af4a5a13a15fa0c60e06321077ef452f769b42fd" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ab9b24a82b305e059921a24ce81be4681714db8e790d8dd5de2bbbcec6eeff6d
[INFO] running `Command { std: "docker" "start" "-a" "ab9b24a82b305e059921a24ce81be4681714db8e790d8dd5de2bbbcec6eeff6d", kill_on_drop: false }`
[INFO] [stderr]     Checking rand_core v0.3.0
[INFO] [stderr]     Checking libc v0.2.43
[INFO] [stderr]     Checking rand_core v0.2.2
[INFO] [stderr]     Checking rand v0.5.5
[INFO] [stderr]     Checking rust_learning v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0601]: `main` function not found in crate `refcall`
[INFO] [stdout]   --> src/refcall.rs:66:2
[INFO] [stdout]    |
[INFO] [stdout] 66 | }
[INFO] [stdout]    |  ^ consider adding a `main` function to `src/refcall.rs`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]   --> src/struct.rs:14:7
[INFO] [stdout]    |
[INFO] [stdout] 14 |   let user2 = User {
[INFO] [stdout]    |       ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]   --> src/struct.rs:20:7
[INFO] [stdout]    |
[INFO] [stdout] 20 |   let black = Color(0, 0, 0);
[INFO] [stdout]    |       ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `username`, `email`, `sign_in_count`, and `active` are never read
[INFO] [stdout]  --> src/struct.rs:2:3
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct User {
[INFO] [stdout]   |        ---- fields in this struct
[INFO] [stdout] 2 |   username: String,
[INFO] [stdout]   |   ^^^^^^^^
[INFO] [stdout] 3 |   email: String,
[INFO] [stdout]   |   ^^^^^
[INFO] [stdout] 4 |   sign_in_count: u64,
[INFO] [stdout]   |   ^^^^^^^^^^^^^
[INFO] [stdout] 5 |   active: bool
[INFO] [stdout]   |   ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::rc::Rc`
[INFO] [stdout]  --> src/shared_mem.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::rc::Rc;
[INFO] [stdout]   |     ^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, and `2` are never read
[INFO] [stdout]  --> src/struct.rs:8:14
[INFO] [stdout]   |
[INFO] [stdout] 8 | struct Color(i32, i32, i32);
[INFO] [stdout]   |        ----- ^^^  ^^^  ^^^
[INFO] [stdout]   |        |
[INFO] [stdout]   |        fields in this struct
[INFO] [stdout]   |
[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] 8 | struct Color((), (), ());
[INFO] [stdout]   |              ~~  ~~  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0601`.
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/slice.rs:2:7
[INFO] [stdout]   |
[INFO] [stdout] 2 |   let mut s = String::from("hello world");
[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: unused import: `std::time::Duration`
[INFO] [stdout]  --> src/multiple_thread.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::time::Duration;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s6`
[INFO] [stdout]   --> src/owner.rs:19:7
[INFO] [stdout]    |
[INFO] [stdout] 19 |   let s6 = s5;
[INFO] [stdout]    |       ^^ help: if this is intentional, prefix it with an underscore: `_s6`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `s6`
[INFO] [stdout]   --> src/owner.rs:19:7
[INFO] [stdout]    |
[INFO] [stdout] 19 |   let s6 = s5;
[INFO] [stdout]    |       ^^ help: if this is intentional, prefix it with an underscore: `_s6`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `user2`
[INFO] [stdout]   --> src/struct.rs:14:7
[INFO] [stdout]    |
[INFO] [stdout] 14 |   let user2 = User {
[INFO] [stdout]    |       ^^^^^ help: if this is intentional, prefix it with an underscore: `_user2`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `black`
[INFO] [stdout]   --> src/struct.rs:20:7
[INFO] [stdout]    |
[INFO] [stdout] 20 |   let black = Color(0, 0, 0);
[INFO] [stdout]    |       ^^^^^ help: if this is intentional, prefix it with an underscore: `_black`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `gives_ownership` is never used
[INFO] [stdout]   --> src/owner.rs:37:4
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn gives_ownership() -> String {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]  --> src/rc.rs:7:10
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout]   |     ---- ^^^^^^^^^^^^^^^^  ^^^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     fields in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[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] 7 |     Cons((), ()),
[INFO] [stdout]   |          ~~  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rust_learning` (bin "refcall") due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: function `gives_ownership` is never used
[INFO] [stdout]   --> src/owner.rs:37:4
[INFO] [stdout]    |
[INFO] [stdout] 37 | fn gives_ownership() -> String {
[INFO] [stdout]    |    ^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `username`, `email`, `sign_in_count`, and `active` are never read
[INFO] [stdout]  --> src/struct.rs:2:3
[INFO] [stdout]   |
[INFO] [stdout] 1 | struct User {
[INFO] [stdout]   |        ---- fields in this struct
[INFO] [stdout] 2 |   username: String,
[INFO] [stdout]   |   ^^^^^^^^
[INFO] [stdout] 3 |   email: String,
[INFO] [stdout]   |   ^^^^^
[INFO] [stdout] 4 |   sign_in_count: u64,
[INFO] [stdout]   |   ^^^^^^^^^^^^^
[INFO] [stdout] 5 |   active: bool
[INFO] [stdout]   |   ^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0`, `1`, and `2` are never read
[INFO] [stdout]  --> src/struct.rs:8:14
[INFO] [stdout]   |
[INFO] [stdout] 8 | struct Color(i32, i32, i32);
[INFO] [stdout]   |        ----- ^^^  ^^^  ^^^
[INFO] [stdout]   |        |
[INFO] [stdout]   |        fields in this struct
[INFO] [stdout]   |
[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] 8 | struct Color((), (), ());
[INFO] [stdout]   |              ~~  ~~  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `six`
[INFO] [stdout]   --> src/match.rs:25:7
[INFO] [stdout]    |
[INFO] [stdout] 25 |   let six = plus_one(five);
[INFO] [stdout]    |       ^^^ help: if this is intentional, prefix it with an underscore: `_six`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `none`
[INFO] [stdout]   --> src/match.rs:26:7
[INFO] [stdout]    |
[INFO] [stdout] 26 |   let none = plus_one(None);
[INFO] [stdout]    |       ^^^^ help: if this is intentional, prefix it with an underscore: `_none`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variants `Penny`, `Nickel`, and `Dime` are never constructed
[INFO] [stdout]  --> src/match.rs:2:3
[INFO] [stdout]   |
[INFO] [stdout] 1 | enum Coin {
[INFO] [stdout]   |      ---- variants in this enum
[INFO] [stdout] 2 |   Penny,
[INFO] [stdout]   |   ^^^^^
[INFO] [stdout] 3 |   Nickel,
[INFO] [stdout]   |   ^^^^^^
[INFO] [stdout] 4 |   Dime,
[INFO] [stdout]   |   ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant `Alabama` is never constructed
[INFO] [stdout]   --> src/match.rs:10:3
[INFO] [stdout]    |
[INFO] [stdout] 9  | enum UsState {
[INFO] [stdout]    |      ------- variant in this enum
[INFO] [stdout] 10 |   Alabama,
[INFO] [stdout]    |   ^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `UsState` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]  --> src/rc.rs:7:10
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout]   |     ---- ^^^^^^^^^^^^^^^^  ^^^^^^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     fields in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[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] 7 |     Cons((), ()),
[INFO] [stdout]   |          ~~  ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "ab9b24a82b305e059921a24ce81be4681714db8e790d8dd5de2bbbcec6eeff6d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ab9b24a82b305e059921a24ce81be4681714db8e790d8dd5de2bbbcec6eeff6d", kill_on_drop: false }`
[INFO] [stdout] ab9b24a82b305e059921a24ce81be4681714db8e790d8dd5de2bbbcec6eeff6d