[INFO] fetching crate challenge-prompt 0.2.0...
[INFO] checking challenge-prompt-0.2.0 against master#a609fb45efad59dfd459c76e50899be9f0583b5a for pr-80579
[INFO] extracting crate challenge-prompt 0.2.0 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate challenge-prompt 0.2.0 on toolchain a609fb45efad59dfd459c76e50899be9f0583b5a
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "read-manifest" "--manifest-path" "Cargo.toml", 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-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "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" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "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] 4b9f814aa1a51cd5681bc2e5db8a0c6a590d49fbeac318710dfa08d559117acc
[INFO] running `Command { std: "docker" "start" "-a" "4b9f814aa1a51cd5681bc2e5db8a0c6a590d49fbeac318710dfa08d559117acc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4b9f814aa1a51cd5681bc2e5db8a0c6a590d49fbeac318710dfa08d559117acc", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4b9f814aa1a51cd5681bc2e5db8a0c6a590d49fbeac318710dfa08d559117acc", kill_on_drop: false }`
[INFO] [stdout] 4b9f814aa1a51cd5681bc2e5db8a0c6a590d49fbeac318710dfa08d559117acc
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+a609fb45efad59dfd459c76e50899be9f0583b5a" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 773c06c1f44c1e11efa25574107126f0c48f54e4842564152fe061206c47d5e5
[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" "773c06c1f44c1e11efa25574107126f0c48f54e4842564152fe061206c47d5e5", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.56
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling serde_derive v1.0.118
[INFO] [stderr]    Compiling serde v1.0.118
[INFO] [stderr]    Compiling libc v0.2.81
[INFO] [stderr]    Compiling serde_json v1.0.61
[INFO] [stderr]     Checking predicates-core v0.9.0
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]    Compiling escargot v0.3.1
[INFO] [stderr]     Checking normalize-line-endings v0.2.2
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking predicates-tree v0.9.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]     Checking rand v0.5.6
[INFO] [stderr]     Checking float-cmp v0.4.0
[INFO] [stderr]     Checking predicates v0.9.1
[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 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 38.77s
[INFO] running `Command { std: "docker" "inspect" "773c06c1f44c1e11efa25574107126f0c48f54e4842564152fe061206c47d5e5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "773c06c1f44c1e11efa25574107126f0c48f54e4842564152fe061206c47d5e5", kill_on_drop: false }`
[INFO] [stdout] 773c06c1f44c1e11efa25574107126f0c48f54e4842564152fe061206c47d5e5