[INFO] cloning repository https://github.com/sumanshil/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/sumanshil/error_handling" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsumanshil%2Ferror_handling", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsumanshil%2Ferror_handling'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 006d26f5de07a6d81df12d8785d9f66e8a28e615
[INFO] checking sumanshil/error_handling against try#26ad8a85dc4eed299af809e52f278da81e284602 for pr-138458
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsumanshil%2Ferror_handling" "/workspace/builds/worker-6-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/sumanshil/error_handling on toolchain 26ad8a85dc4eed299af809e52f278da81e284602
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+26ad8a85dc4eed299af809e52f278da81e284602" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/sumanshil/error_handling
[INFO] finished tweaking git repo https://github.com/sumanshil/error_handling
[INFO] tweaked toml for git repo https://github.com/sumanshil/error_handling written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/sumanshil/error_handling 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" "+26ad8a85dc4eed299af809e52f278da81e284602" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+26ad8a85dc4eed299af809e52f278da81e284602" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] c2a8b57e754d7d54f5d738a700d96d46b86ffe9469a58e94c82a229f2aae8147
[INFO] running `Command { std: "docker" "start" "-a" "c2a8b57e754d7d54f5d738a700d96d46b86ffe9469a58e94c82a229f2aae8147", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c2a8b57e754d7d54f5d738a700d96d46b86ffe9469a58e94c82a229f2aae8147", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c2a8b57e754d7d54f5d738a700d96d46b86ffe9469a58e94c82a229f2aae8147", kill_on_drop: false }`
[INFO] [stdout] c2a8b57e754d7d54f5d738a700d96d46b86ffe9469a58e94c82a229f2aae8147
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/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@sha256:1680c8fbd8dfb46fcd6d22e546df16ab0e007457dc29fcd9e987cdd5077fd1af" "/opt/rustwide/cargo-home/bin/cargo" "+26ad8a85dc4eed299af809e52f278da81e284602" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 6b126561cf167dd1f76f194975676122e4c8a37aaaa2a621a54b2b1f180c2086
[INFO] running `Command { std: "docker" "start" "-a" "6b126561cf167dd1f76f194975676122e4c8a37aaaa2a621a54b2b1f180c2086", kill_on_drop: false }`
[INFO] [stderr]     Checking error-handling v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]  --> src/main.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 |    File::create(file)?.write_all(b"Hello");
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]   = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]   |
[INFO] [stdout] 9 |    let _ = File::create(file)?.write_all(b"Hello");
[INFO] [stdout]   |    +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]  --> src/main.rs:9:4
[INFO] [stdout]   |
[INFO] [stdout] 9 |    File::create(file)?.write_all(b"Hello");
[INFO] [stdout]   |    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout]   = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]   |
[INFO] [stdout] 9 |    let _ = File::create(file)?.write_all(b"Hello");
[INFO] [stdout]   |    +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.30s
[INFO] running `Command { std: "docker" "inspect" "6b126561cf167dd1f76f194975676122e4c8a37aaaa2a621a54b2b1f180c2086", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b126561cf167dd1f76f194975676122e4c8a37aaaa2a621a54b2b1f180c2086", kill_on_drop: false }`
[INFO] [stdout] 6b126561cf167dd1f76f194975676122e4c8a37aaaa2a621a54b2b1f180c2086