[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 1.60.0 for beta-1.61-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Farnaudj%2Frust-playground" "/workspace/builds/worker-63/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-63/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/arnaudj/rust-playground on toolchain 1.60.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "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-63/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" "+1.60.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 135a0a5e9c7d0cf4caf2db7beadfeee117fbda14c2f59629f613173d29fb68ae
[INFO] running `Command { std: "docker" "start" "-a" "135a0a5e9c7d0cf4caf2db7beadfeee117fbda14c2f59629f613173d29fb68ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "135a0a5e9c7d0cf4caf2db7beadfeee117fbda14c2f59629f613173d29fb68ae", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "135a0a5e9c7d0cf4caf2db7beadfeee117fbda14c2f59629f613173d29fb68ae", kill_on_drop: false }`
[INFO] [stdout] 135a0a5e9c7d0cf4caf2db7beadfeee117fbda14c2f59629f613173d29fb68ae
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-63/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a5ea0467d5853fb88af30b39f4ddd35dd4370d6eaaa9f554417645fa6b5a2cf1
[INFO] running `Command { std: "docker" "start" "-a" "a5ea0467d5853fb88af30b39f4ddd35dd4370d6eaaa9f554417645fa6b5a2cf1", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.101
[INFO] [stderr]    Compiling ppv-lite86 v0.2.10
[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] [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] [stderr] error: could not compile `tuto1` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "a5ea0467d5853fb88af30b39f4ddd35dd4370d6eaaa9f554417645fa6b5a2cf1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a5ea0467d5853fb88af30b39f4ddd35dd4370d6eaaa9f554417645fa6b5a2cf1", kill_on_drop: false }`
[INFO] [stdout] a5ea0467d5853fb88af30b39f4ddd35dd4370d6eaaa9f554417645fa6b5a2cf1