[INFO] cloning repository https://github.com/VitalyAnkh/learn_error_handling
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/VitalyAnkh/learn_error_handling" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVitalyAnkh%2Flearn_error_handling", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVitalyAnkh%2Flearn_error_handling'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a9cf67b08bbfba5b416953d982e1a8eada6ad2f8
[INFO] checking VitalyAnkh/learn_error_handling against beta-2020-07-24 for pr-75494-beta
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FVitalyAnkh%2Flearn_error_handling" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/VitalyAnkh/learn_error_handling on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/VitalyAnkh/learn_error_handling
[INFO] finished tweaking git repo https://github.com/VitalyAnkh/learn_error_handling
[INFO] tweaked toml for git repo https://github.com/VitalyAnkh/learn_error_handling written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/VitalyAnkh/learn_error_handling already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d0cbb6922fbb13a4019d57a82f1d66ec824d232f21c801fea62b836949a6b8ea
[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" "d0cbb6922fbb13a4019d57a82f1d66ec824d232f21c801fea62b836949a6b8ea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d0cbb6922fbb13a4019d57a82f1d66ec824d232f21c801fea62b836949a6b8ea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d0cbb6922fbb13a4019d57a82f1d66ec824d232f21c801fea62b836949a6b8ea", kill_on_drop: false }`
[INFO] [stdout] d0cbb6922fbb13a4019d57a82f1d66ec824d232f21c801fea62b836949a6b8ea
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8c78f2801e9813e012809a7945c6b8512d19f66071427791e6796c61c49e2135
[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" "8c78f2801e9813e012809a7945c6b8512d19f66071427791e6796c61c49e2135", kill_on_drop: false }`
[INFO] [stderr]     Checking learn_error_handling v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/smart_pointer/rc.rs:12:9
[INFO] [stdout]    |
[INFO] [stdout] 12 |     let b = Cons(2,Rc::clone(&a));
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]  --> src/smart_pointer/ref_cell.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let mut y =&a;
[INFO] [stdout]   |         ^^^^^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/smart_pointer/ref_cell.rs:4:9
[INFO] [stdout]   |
[INFO] [stdout] 4 |     let mut y =&a;
[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: `value`
[INFO] [stdout]  --> src/read/mod.rs:6:5
[INFO] [stdout]   |
[INFO] [stdout] 6 |     value: u32
[INFO] [stdout]   |     ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: comparison is useless due to type limits
[INFO] [stdout]   --> src/read/mod.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 11 |         if value < 0 || value > 100 {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_comparisons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Cons`, `Nil`
[INFO] [stdout]  --> src/smart_pointer/rc.rs:7:18
[INFO] [stdout]   |
[INFO] [stdout] 7 | use self::List::{Cons,Nil};
[INFO] [stdout]   |                  ^^^^ ^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Guess`
[INFO] [stdout]  --> src/read/mod.rs:5:8
[INFO] [stdout]   |
[INFO] [stdout] 5 | struct Guess {
[INFO] [stdout]   |        ^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `new`
[INFO] [stdout]   --> src/read/mod.rs:10:8
[INFO] [stdout]    |
[INFO] [stdout] 10 |     fn new(value: u32) -> Guess {
[INFO] [stdout]    |        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `List`
[INFO] [stdout]  --> src/smart_pointer/rc.rs:1:6
[INFO] [stdout]   |
[INFO] [stdout] 1 | enum List{
[INFO] [stdout]   |      ^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: comparison is useless due to type limits
[INFO] [stdout]   --> src/read/mod.rs:11:12
[INFO] [stdout]    |
[INFO] [stdout] 11 |         if value < 0 || value > 100 {
[INFO] [stdout]    |            ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_comparisons)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `y`
[INFO] [stdout]   --> tests/integration_test.rs:11:9
[INFO] [stdout]    |
[INFO] [stdout] 11 |     let y =&a;
[INFO] [stdout]    |         ^ help: if this is intentional, prefix it with an underscore: `_y`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `it_add_two`
[INFO] [stdout]  --> tests/integration_test.rs:5:4
[INFO] [stdout]   |
[INFO] [stdout] 5 | fn it_add_two(){
[INFO] [stdout]   |    ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `check_borrow_rules`
[INFO] [stdout]  --> tests/integration_test.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 | fn check_borrow_rules(){
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.38s
[INFO] running `Command { std: "docker" "inspect" "8c78f2801e9813e012809a7945c6b8512d19f66071427791e6796c61c49e2135", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c78f2801e9813e012809a7945c6b8512d19f66071427791e6796c61c49e2135", kill_on_drop: false }`
[INFO] [stdout] 8c78f2801e9813e012809a7945c6b8512d19f66071427791e6796c61c49e2135
