[INFO] fetching crate challenge-prompt 0.2.0...
[INFO] checking challenge-prompt-0.2.0 against master#9fa580b1175018b0a276b0bc68f9827a106f7260 for pr-82565
[INFO] extracting crate challenge-prompt 0.2.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate challenge-prompt 0.2.0 on toolchain 9fa580b1175018b0a276b0bc68f9827a106f7260
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9fa580b1175018b0a276b0bc68f9827a106f7260" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate challenge-prompt 0.2.0
[INFO] finished tweaking crates.io crate challenge-prompt 0.2.0
[INFO] tweaked toml for crates.io crate challenge-prompt 0.2.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9fa580b1175018b0a276b0bc68f9827a106f7260" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9fa580b1175018b0a276b0bc68f9827a106f7260" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+9fa580b1175018b0a276b0bc68f9827a106f7260" "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] 2de142d1e1512bcf31e77b52d71333f66c7b8bbeda25ae873123985c619e828e
[INFO] running `Command { std: "docker" "start" "-a" "2de142d1e1512bcf31e77b52d71333f66c7b8bbeda25ae873123985c619e828e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2de142d1e1512bcf31e77b52d71333f66c7b8bbeda25ae873123985c619e828e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2de142d1e1512bcf31e77b52d71333f66c7b8bbeda25ae873123985c619e828e", kill_on_drop: false }`
[INFO] [stdout] 2de142d1e1512bcf31e77b52d71333f66c7b8bbeda25ae873123985c619e828e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+9fa580b1175018b0a276b0bc68f9827a106f7260" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ba2b13f3a7a6ebb576010acc4f2d8059264f978fa24988af6f974ce9668bdc0d
[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" "ba2b13f3a7a6ebb576010acc4f2d8059264f978fa24988af6f974ce9668bdc0d", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.63
[INFO] [stderr]    Compiling escargot v0.3.1
[INFO] [stderr]     Checking predicates-core v0.9.0
[INFO] [stderr]     Checking regex-syntax v0.6.23
[INFO] [stderr]     Checking difference v2.0.0
[INFO] [stderr]     Checking normalize-line-endings v0.2.2
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking rand v0.5.6
[INFO] [stderr]     Checking predicates-tree v0.9.0
[INFO] [stderr]     Checking challenge-prompt v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the item `rand` is imported redundantly
[INFO] [stdout]   --> src/lib.rs:55:13
[INFO] [stdout]    |
[INFO] [stdout] 40 | extern crate rand;
[INFO] [stdout]    | ------------------ the item `rand` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 55 |         use rand;
[INFO] [stdout]    |             ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking float-cmp v0.4.0
[INFO] [stderr]     Checking regex v1.4.4
[INFO] [stderr]    Compiling serde_derive v1.0.124
[INFO] [stderr]     Checking predicates v0.9.1
[INFO] [stderr]     Checking serde v1.0.124
[INFO] [stderr]     Checking serde_json v1.0.64
[INFO] [stderr]     Checking assert_cmd v0.9.1
[INFO] [stdout] warning: the item `rand` is imported redundantly
[INFO] [stdout]   --> src/lib.rs:55:13
[INFO] [stdout]    |
[INFO] [stdout] 40 | extern crate rand;
[INFO] [stdout]    | ------------------ the item `rand` is already imported here
[INFO] [stdout] ...
[INFO] [stdout] 55 |         use rand;
[INFO] [stdout]    |             ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 31.63s
[INFO] running `Command { std: "docker" "inspect" "ba2b13f3a7a6ebb576010acc4f2d8059264f978fa24988af6f974ce9668bdc0d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba2b13f3a7a6ebb576010acc4f2d8059264f978fa24988af6f974ce9668bdc0d", kill_on_drop: false }`
[INFO] [stdout] ba2b13f3a7a6ebb576010acc4f2d8059264f978fa24988af6f974ce9668bdc0d