[INFO] cloning repository https://github.com/arnaudj/rust-playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/arnaudj/rust-playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farnaudj%2Frust-playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farnaudj%2Frust-playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 2f5b032fa32e374c1ffdb3e9819dbfab8525c8af
[INFO] testing arnaudj/rust-playground against 1.59.0 for beta-1.60-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farnaudj%2Frust-playground" "/workspace/builds/worker-13/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-13/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/arnaudj/rust-playground on toolchain 1.59.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/arnaudj/rust-playground
[INFO] finished tweaking git repo https://github.com/arnaudj/rust-playground
[INFO] tweaked toml for git repo https://github.com/arnaudj/rust-playground written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] crate git repo https://github.com/arnaudj/rust-playground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f2cd47a2b546a9a1b942edf4c495f5181b893be9203b466b5f27e760d7398aff
[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" "f2cd47a2b546a9a1b942edf4c495f5181b893be9203b466b5f27e760d7398aff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f2cd47a2b546a9a1b942edf4c495f5181b893be9203b466b5f27e760d7398aff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f2cd47a2b546a9a1b942edf4c495f5181b893be9203b466b5f27e760d7398aff", kill_on_drop: false }`
[INFO] [stdout] f2cd47a2b546a9a1b942edf4c495f5181b893be9203b466b5f27e760d7398aff
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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=warn" "-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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ed0f542649aa258832b56ef42e203501566017e1259bbde5cfc2bfffd0130040
[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" "ed0f542649aa258832b56ef42e203501566017e1259bbde5cfc2bfffd0130040", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.101
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.4
[INFO] [stderr]    Compiling tuto1 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0277]: the `?` operator can only be used in a function that returns `Result` or `Option` (or another type that implements `FromResidual`)
[INFO] [stdout]   --> src/main.rs:34:35
[INFO] [stdout]    |
[INFO] [stdout] 32 | / fn test_unwrap() {
[INFO] [stdout] 33 | |     use std::fs::File;
[INFO] [stdout] 34 | |     let mut f = File::open("test")?;
[INFO] [stdout]    | |                                   ^ cannot use the `?` operator in a function that returns `()`
[INFO] [stdout] 35 | | }
[INFO] [stdout]    | |_- this function should return `Result` or `Option` to accept `?`
[INFO] [stdout]    |
[INFO] [stdout]    = help: the trait `FromResidual<Result<Infallible, std::io::Error>>` is not implemented for `()`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tuto1` due to 2 previous errors
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0277`.
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "ed0f542649aa258832b56ef42e203501566017e1259bbde5cfc2bfffd0130040", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ed0f542649aa258832b56ef42e203501566017e1259bbde5cfc2bfffd0130040", kill_on_drop: false }`
[INFO] [stdout] ed0f542649aa258832b56ef42e203501566017e1259bbde5cfc2bfffd0130040