[INFO] fetching crate json_flex 0.3.3...
[INFO] checking json_flex-0.3.3 against master#d62d3f7fa9a91d933213cc10e20e740608983f64 for pr-77015
[INFO] extracting crate json_flex 0.3.3 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate json_flex 0.3.3 on toolchain d62d3f7fa9a91d933213cc10e20e740608983f64
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate json_flex 0.3.3
[INFO] finished tweaking crates.io crate json_flex 0.3.3
[INFO] tweaked toml for crates.io crate json_flex 0.3.3 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a3524ce55b10122243c70f80ebf1d5a35b49552687cc5bfb58127c0b1a2d4ab3
[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" "a3524ce55b10122243c70f80ebf1d5a35b49552687cc5bfb58127c0b1a2d4ab3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a3524ce55b10122243c70f80ebf1d5a35b49552687cc5bfb58127c0b1a2d4ab3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a3524ce55b10122243c70f80ebf1d5a35b49552687cc5bfb58127c0b1a2d4ab3", kill_on_drop: false }`
[INFO] [stdout] a3524ce55b10122243c70f80ebf1d5a35b49552687cc5bfb58127c0b1a2d4ab3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+d62d3f7fa9a91d933213cc10e20e740608983f64" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 773c9ab6e731b799e684c31215dcf5b69ed7aaeab16287f039525c08c377dc78
[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" "773c9ab6e731b799e684c31215dcf5b69ed7aaeab16287f039525c08c377dc78", kill_on_drop: false }`
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]     Checking json_flex v0.3.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::fs::File`
[INFO] [stdout]  --> src/test.rs:4:5
[INFO] [stdout]   |
[INFO] [stdout] 4 | use std::fs::File;
[INFO] [stdout]   |     ^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `std::io::prelude::*`
[INFO] [stdout]  --> src/test.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use std::io::prelude::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.24s
[INFO] running `Command { std: "docker" "inspect" "773c9ab6e731b799e684c31215dcf5b69ed7aaeab16287f039525c08c377dc78", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "773c9ab6e731b799e684c31215dcf5b69ed7aaeab16287f039525c08c377dc78", kill_on_drop: false }`
[INFO] [stdout] 773c9ab6e731b799e684c31215dcf5b69ed7aaeab16287f039525c08c377dc78