[INFO] cloning repository https://github.com/dandelion-blanc/practice03_file_io
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/dandelion-blanc/practice03_file_io" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdandelion-blanc%2Fpractice03_file_io", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdandelion-blanc%2Fpractice03_file_io'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 159d791aef8ac6ea074fc75256178c78bdaaa418
[INFO] checking dandelion-blanc/practice03_file_io against master#30662530506ed29ea29191798cb2ab8aa1249023 for pr-120227
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdandelion-blanc%2Fpractice03_file_io" "/workspace/builds/worker-5-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dandelion-blanc/practice03_file_io on toolchain 30662530506ed29ea29191798cb2ab8aa1249023
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+30662530506ed29ea29191798cb2ab8aa1249023" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dandelion-blanc/practice03_file_io
[INFO] finished tweaking git repo https://github.com/dandelion-blanc/practice03_file_io
[INFO] tweaked toml for git repo https://github.com/dandelion-blanc/practice03_file_io written to /workspace/builds/worker-5-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/dandelion-blanc/practice03_file_io 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" "+30662530506ed29ea29191798cb2ab8aa1249023" "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
[ERROR] error running command: no output for 300 seconds
[ERROR] this task or one of its parent failed!
[ERROR] no output for 300 seconds
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.
[INFO] checking dandelion-blanc/practice03_file_io against try#ad2e3884fa8975e4827c1b0b0af203fc59856ef2 for pr-120227
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdandelion-blanc%2Fpractice03_file_io" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dandelion-blanc/practice03_file_io on toolchain ad2e3884fa8975e4827c1b0b0af203fc59856ef2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ad2e3884fa8975e4827c1b0b0af203fc59856ef2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dandelion-blanc/practice03_file_io
[INFO] finished tweaking git repo https://github.com/dandelion-blanc/practice03_file_io
[INFO] tweaked toml for git repo https://github.com/dandelion-blanc/practice03_file_io written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/dandelion-blanc/practice03_file_io 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" "+ad2e3884fa8975e4827c1b0b0af203fc59856ef2" "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
[ERROR] error running command: no output for 300 seconds
[INFO] checking dandelion-blanc/practice03_file_io against try#ad2e3884fa8975e4827c1b0b0af203fc59856ef2 for pr-120227
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdandelion-blanc%2Fpractice03_file_io" "/workspace/builds/worker-5-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5-tc2/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/dandelion-blanc/practice03_file_io on toolchain ad2e3884fa8975e4827c1b0b0af203fc59856ef2
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+ad2e3884fa8975e4827c1b0b0af203fc59856ef2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/dandelion-blanc/practice03_file_io
[INFO] finished tweaking git repo https://github.com/dandelion-blanc/practice03_file_io
[INFO] tweaked toml for git repo https://github.com/dandelion-blanc/practice03_file_io written to /workspace/builds/worker-5-tc2/source/Cargo.toml
[INFO] crate git repo https://github.com/dandelion-blanc/practice03_file_io 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" "+ad2e3884fa8975e4827c1b0b0af203fc59856ef2" "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-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ad2e3884fa8975e4827c1b0b0af203fc59856ef2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 008c7065fd47268d4f20d46ddf5ab5bd474ceb1134a6633842d3af82ca218748
[INFO] running `Command { std: "docker" "start" "-a" "008c7065fd47268d4f20d46ddf5ab5bd474ceb1134a6633842d3af82ca218748", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "008c7065fd47268d4f20d46ddf5ab5bd474ceb1134a6633842d3af82ca218748", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "008c7065fd47268d4f20d46ddf5ab5bd474ceb1134a6633842d3af82ca218748", kill_on_drop: false }`
[INFO] [stdout] 008c7065fd47268d4f20d46ddf5ab5bd474ceb1134a6633842d3af82ca218748
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5-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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+ad2e3884fa8975e4827c1b0b0af203fc59856ef2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 948c8fa3c2ecf7375b6d5b4c3811f07000245fc85ef2a12b47b39e01902da0c7
[INFO] running `Command { std: "docker" "start" "-a" "948c8fa3c2ecf7375b6d5b4c3811f07000245fc85ef2a12b47b39e01902da0c7", kill_on_drop: false }`
[INFO] [stderr]     Checking practice03_file_io v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/main.rs:28:29
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn main() -> Result<(), Box<std::error::Error>>
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn main() -> Result<(), Box<dyn std::error::Error>>
[INFO] [stdout]    |                             +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/main.rs:28:29
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn main() -> Result<(), Box<std::error::Error>>
[INFO] [stdout]    |                             ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this is accepted in the current edition (Rust 2018) but is a hard error in Rust 2021!
[INFO] [stdout]    = note: for more information, see <https://doc.rust-lang.org/nightly/edition-guide/rust-2021/warnings-promoted-to-error.html>
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout] help: use `dyn`
[INFO] [stdout]    |
[INFO] [stdout] 28 | fn main() -> Result<(), Box<dyn std::error::Error>>
[INFO] [stdout]    |                             +++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `string_line` is never used
[INFO] [stdout]   --> src/main.rs:15:4
[INFO] [stdout]    |
[INFO] [stdout] 15 | fn string_line(s: &String) -> &str
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function `string_line` is never used
[INFO] [stdout]   --> src/main.rs:15:4
[INFO] [stdout]    |
[INFO] [stdout] 15 | fn string_line(s: &String) -> &str
[INFO] [stdout]    |    ^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.07s
[INFO] running `Command { std: "docker" "inspect" "948c8fa3c2ecf7375b6d5b4c3811f07000245fc85ef2a12b47b39e01902da0c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "948c8fa3c2ecf7375b6d5b4c3811f07000245fc85ef2a12b47b39e01902da0c7", kill_on_drop: false }`
[INFO] [stdout] 948c8fa3c2ecf7375b6d5b4c3811f07000245fc85ef2a12b47b39e01902da0c7