[INFO] fetching crate json_flex 0.3.3...
[INFO] checking json_flex-0.3.3 against try#f47dd4da3ae8c32c9e65d307bfe640b143e674df for pr-77526
[INFO] extracting crate json_flex 0.3.3 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate json_flex 0.3.3 on toolchain f47dd4da3ae8c32c9e65d307bfe640b143e674df
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "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-9/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 1332a3ad21fbcdadcbb566c1971dd10b9efbfbf3ecbac19745f19453b2163508
[INFO] running `Command { std: "docker" "start" "-a" "1332a3ad21fbcdadcbb566c1971dd10b9efbfbf3ecbac19745f19453b2163508", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1332a3ad21fbcdadcbb566c1971dd10b9efbfbf3ecbac19745f19453b2163508", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1332a3ad21fbcdadcbb566c1971dd10b9efbfbf3ecbac19745f19453b2163508", kill_on_drop: false }`
[INFO] [stdout] 1332a3ad21fbcdadcbb566c1971dd10b9efbfbf3ecbac19745f19453b2163508
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "+f47dd4da3ae8c32c9e65d307bfe640b143e674df" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 252540fe519dc2f071d9faa1ff34b8b2bed84b2d449ecab856e7817f55dfe28f
[INFO] running `Command { std: "docker" "start" "-a" "252540fe519dc2f071d9faa1ff34b8b2bed84b2d449ecab856e7817f55dfe28f", 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 5.20s
[INFO] running `Command { std: "docker" "inspect" "252540fe519dc2f071d9faa1ff34b8b2bed84b2d449ecab856e7817f55dfe28f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "252540fe519dc2f071d9faa1ff34b8b2bed84b2d449ecab856e7817f55dfe28f", kill_on_drop: false }`
[INFO] [stdout] 252540fe519dc2f071d9faa1ff34b8b2bed84b2d449ecab856e7817f55dfe28f