[INFO] cloning repository https://github.com/GrayStrider/playground-rust-book
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/GrayStrider/playground-rust-book" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FGrayStrider%2Fplayground-rust-book", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FGrayStrider%2Fplayground-rust-book'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bd341c23ce48da1b2611c5ee517e5a95c5bc8a50
[INFO] checking GrayStrider/playground-rust-book against try#7306d3110618f84a6a4662b9e2cc4fd0d9b02da8 for pr-97346
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FGrayStrider%2Fplayground-rust-book" "/workspace/builds/worker-3/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/GrayStrider/playground-rust-book on toolchain 7306d3110618f84a6a4662b9e2cc4fd0d9b02da8
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+7306d3110618f84a6a4662b9e2cc4fd0d9b02da8" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/GrayStrider/playground-rust-book
[INFO] finished tweaking git repo https://github.com/GrayStrider/playground-rust-book
[INFO] tweaked toml for git repo https://github.com/GrayStrider/playground-rust-book written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/GrayStrider/playground-rust-book already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+7306d3110618f84a6a4662b9e2cc4fd0d9b02da8" "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-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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:ac0d0aa6ec8ed129e241004a6179c99fa0d2616f50ba759c5b60bd26d0fafa02" "/opt/rustwide/cargo-home/bin/cargo" "+7306d3110618f84a6a4662b9e2cc4fd0d9b02da8" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 5c1fa37ace9a415d95489459d3b238f968d80f7e5a76b0fe029fde853ff9ed00
[INFO] running `Command { std: "docker" "start" "-a" "5c1fa37ace9a415d95489459d3b238f968d80f7e5a76b0fe029fde853ff9ed00", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5c1fa37ace9a415d95489459d3b238f968d80f7e5a76b0fe029fde853ff9ed00", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5c1fa37ace9a415d95489459d3b238f968d80f7e5a76b0fe029fde853ff9ed00", kill_on_drop: false }`
[INFO] [stdout] 5c1fa37ace9a415d95489459d3b238f968d80f7e5a76b0fe029fde853ff9ed00
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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:ac0d0aa6ec8ed129e241004a6179c99fa0d2616f50ba759c5b60bd26d0fafa02" "/opt/rustwide/cargo-home/bin/cargo" "+7306d3110618f84a6a4662b9e2cc4fd0d9b02da8" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b551182df71378808c1acfb6031a38c3d497e305e4625fcf4a150ea533ab4998
[INFO] running `Command { std: "docker" "start" "-a" "b551182df71378808c1acfb6031a38c3d497e305e4625fcf4a150ea533ab4998", kill_on_drop: false }`
[INFO] [stderr]     Checking pipeline v0.5.0
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling num-bigint v0.3.0
[INFO] [stderr]    Compiling num-rational v0.3.0
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]     Checking num-complex v0.3.0
[INFO] [stderr]     Checking num v0.3.0
[INFO] [stderr]     Checking play3 v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/std/vectors_arrays.rs:26:2
[INFO] [stdout]    |
[INFO] [stdout] 26 |     &v[2];
[INFO] [stdout]    |     ^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let _ = &v[2];
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/std/vectors_arrays.rs:27:2
[INFO] [stdout]    |
[INFO] [stdout] 27 |     &a[2];
[INFO] [stdout]    |     ^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let _ = &a[2];
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Chars` that must be used
[INFO] [stdout]   --> src/std/strings.rs:41:2
[INFO] [stdout]    |
[INFO] [stdout] 41 |     word.chars();
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: iterators are lazy and do nothing unless consumed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::str::Bytes` that must be used
[INFO] [stdout]   --> src/std/strings.rs:42:2
[INFO] [stdout]    |
[INFO] [stdout] 42 |     word.bytes();
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: iterators are lazy and do nothing unless consumed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/std/vectors_arrays.rs:26:2
[INFO] [stdout]    |
[INFO] [stdout] 26 |     &v[2];
[INFO] [stdout]    |     ^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 26 |     let _ = &v[2];
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]   --> src/std/vectors_arrays.rs:27:2
[INFO] [stdout]    |
[INFO] [stdout] 27 |     &a[2];
[INFO] [stdout]    |     ^^^^^ the borrow produces a value
[INFO] [stdout]    |
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 27 |     let _ = &a[2];
[INFO] [stdout]    |     +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Chars` that must be used
[INFO] [stdout]   --> src/std/strings.rs:41:2
[INFO] [stdout]    |
[INFO] [stdout] 41 |     word.chars();
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: iterators are lazy and do nothing unless consumed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `std::str::Bytes` that must be used
[INFO] [stdout]   --> src/std/strings.rs:42:2
[INFO] [stdout]    |
[INFO] [stdout] 42 |     word.bytes();
[INFO] [stdout]    |     ^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: iterators are lazy and do nothing unless consumed
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 4 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 3.29s
[INFO] running `Command { std: "docker" "inspect" "b551182df71378808c1acfb6031a38c3d497e305e4625fcf4a150ea533ab4998", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b551182df71378808c1acfb6031a38c3d497e305e4625fcf4a150ea533ab4998", kill_on_drop: false }`
[INFO] [stdout] b551182df71378808c1acfb6031a38c3d497e305e4625fcf4a150ea533ab4998