[INFO] cloning repository https://github.com/km-tr/rustlings
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/km-tr/rustlings" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkm-tr%2Frustlings", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkm-tr%2Frustlings'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 965bd57ff9b3f6c6e9cd16f6e5f779de68ce1f5f
[INFO] checking km-tr/rustlings against master#0a8629bff642c3c3b84bb644c0099194f063b627 for pr-86231
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fkm-tr%2Frustlings" "/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/km-tr/rustlings on toolchain 0a8629bff642c3c3b84bb644c0099194f063b627
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0a8629bff642c3c3b84bb644c0099194f063b627" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/km-tr/rustlings
[INFO] finished tweaking git repo https://github.com/km-tr/rustlings
[INFO] tweaked toml for git repo https://github.com/km-tr/rustlings written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0a8629bff642c3c3b84bb644c0099194f063b627" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0a8629bff642c3c3b84bb644c0099194f063b627" "fetch" "--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" "+0a8629bff642c3c3b84bb644c0099194f063b627" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 741fb62e2fb5c9514dbd677dbb7287195e691cd8ea6802a3fc9cd1ac62559742
[INFO] running `Command { std: "docker" "start" "-a" "741fb62e2fb5c9514dbd677dbb7287195e691cd8ea6802a3fc9cd1ac62559742", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "741fb62e2fb5c9514dbd677dbb7287195e691cd8ea6802a3fc9cd1ac62559742", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "741fb62e2fb5c9514dbd677dbb7287195e691cd8ea6802a3fc9cd1ac62559742", kill_on_drop: false }`
[INFO] [stdout] 741fb62e2fb5c9514dbd677dbb7287195e691cd8ea6802a3fc9cd1ac62559742
[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" "+0a8629bff642c3c3b84bb644c0099194f063b627" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 46fb2d4aa59eba2e74ea0a6dd372eedd9271621d648fd359da36472c74ddc845
[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" "46fb2d4aa59eba2e74ea0a6dd372eedd9271621d648fd359da36472c74ddc845", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.27
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.73
[INFO] [stderr]    Compiling serde_derive v1.0.126
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling serde_json v1.0.64
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling escargot v0.5.2
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]     Checking once_cell v1.8.0
[INFO] [stderr]     Checking tests_intro v0.1.0 (/opt/rustwide/workdir/Writing Automated Tests/Tests/Intro)
[INFO] [stderr]     Checking returning_result v0.1.0 (/opt/rustwide/workdir/Recoverable and Unrecoverable Errors/Error Handling/Returning Result)
[INFO] [stderr]     Checking times_two_tests v0.1.0 (/opt/rustwide/workdir/Writing Automated Tests/Tests Test/Times Two Tests)
[INFO] [stderr]     Checking errorsn v0.1.0 (/opt/rustwide/workdir/Recoverable and Unrecoverable Errors/Error Handling/Multiple Errors)
[INFO] [stderr]     Checking testing_task v0.1.0 (/opt/rustwide/workdir/Writing Automated Tests/Tests/Testing Task)
[INFO] [stdout] error: expected identifier, found `?`
[INFO] [stdout]  --> Recoverable and Unrecoverable Errors/Error Handling/Multiple Errors/src/lib.rs:6:82
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub fn read_and_validate(b: &mut io::BufRead) -> Result<PositiveNonzeroInteger, ???> {
[INFO] [stdout]   |                                                                                  ^ expected identifier
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking if_task v0.1.0 (/opt/rustwide/workdir/Common Programming Concepts/If/If Task)
[INFO] [stdout] warning: associated function is never used: `can_hold`
[INFO] [stdout]  --> Writing Automated Tests/Tests/Intro/src/lib.rs:8:8
[INFO] [stdout]   |
[INFO] [stdout] 8 |     fn can_hold(&self, other: &Rectangle) -> bool {
[INFO] [stdout]   |        ^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `errorsn`
[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: unused import: `std::error::Error`
[INFO] [stdout]  --> Recoverable and Unrecoverable Errors/Error Handling/Returning Result/src/lib.rs:1:5
[INFO] [stdout]   |
[INFO] [stdout] 1 | use std::error::Error;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[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] error[E0308]: mismatched types
[INFO] [stdout]  --> Common Programming Concepts/If/If Task/src/lib.rs:1:34
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn bigger(a: i32, b: i32) -> i32 {
[INFO] [stdout]   |        ------                    ^^^ expected `i32`, found `()`
[INFO] [stdout]   |        |
[INFO] [stdout]   |        implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0308`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "46fb2d4aa59eba2e74ea0a6dd372eedd9271621d648fd359da36472c74ddc845", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "46fb2d4aa59eba2e74ea0a6dd372eedd9271621d648fd359da36472c74ddc845", kill_on_drop: false }`
[INFO] [stdout] 46fb2d4aa59eba2e74ea0a6dd372eedd9271621d648fd359da36472c74ddc845