[INFO] fetching crate prophet 0.4.2...
[INFO] checking prophet-0.4.2 against master#4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5 for pr-81174
[INFO] extracting crate prophet 0.4.2 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate prophet 0.4.2 on toolchain 4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate prophet 0.4.2
[INFO] finished tweaking crates.io crate prophet 0.4.2
[INFO] tweaked toml for crates.io crate prophet 0.4.2 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "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" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "fetch" "--locked" "--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-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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1784374dcedf03bdcc7c2df1621164f4d96cebbd66158e0ebce7795a5d9fb650
[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" "1784374dcedf03bdcc7c2df1621164f4d96cebbd66158e0ebce7795a5d9fb650", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1784374dcedf03bdcc7c2df1621164f4d96cebbd66158e0ebce7795a5d9fb650", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1784374dcedf03bdcc7c2df1621164f4d96cebbd66158e0ebce7795a5d9fb650", kill_on_drop: false }`
[INFO] [stdout] 1784374dcedf03bdcc7c2df1621164f4d96cebbd66158e0ebce7795a5d9fb650
[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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+4d0dd02ee07bddad9136f95c9f7846ebf3eb3fc5" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1a4ba3dcccf36a69e4f84955ec9cd45874d1d9e1967d8e2cb718827a8b123a1e
[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" "1a4ba3dcccf36a69e4f84955ec9cd45874d1d9e1967d8e2cb718827a8b123a1e", kill_on_drop: false }`
[INFO] [stderr]    Compiling ndarray v0.10.14
[INFO] [stderr]     Checking approx v0.1.1
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]     Checking itertools v0.7.11
[INFO] [stderr]     Checking num-complex v0.1.43
[INFO] [stderr]     Checking num-traits v0.1.43
[INFO] [stderr]    Compiling syn v1.0.60
[INFO] [stderr]     Checking log v0.3.9
[INFO] [stderr]     Checking num-bigint v0.1.44
[INFO] [stderr]     Checking num-rational v0.1.42
[INFO] [stderr]     Checking num v0.1.42
[INFO] [stderr]     Checking ndarray-rand v0.6.1
[INFO] [stderr]    Compiling serde_derive v1.0.123
[INFO] [stderr]     Checking prophet v0.4.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `to_owned` that must be used
[INFO] [stdout]    --> src/neural_net.rs:418:4
[INFO] [stdout]     |
[INFO] [stdout] 418 |             layer.calculate_output_gradients(expected.view()).to_owned();
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: cloning is often expensive and is not expected to have side effects
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 24.42s
[INFO] running `Command { std: "docker" "inspect" "1a4ba3dcccf36a69e4f84955ec9cd45874d1d9e1967d8e2cb718827a8b123a1e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a4ba3dcccf36a69e4f84955ec9cd45874d1d9e1967d8e2cb718827a8b123a1e", kill_on_drop: false }`
[INFO] [stdout] 1a4ba3dcccf36a69e4f84955ec9cd45874d1d9e1967d8e2cb718827a8b123a1e