[INFO] fetching crate mnist 0.4.1...
[INFO] checking mnist-0.4.1 against master#0d37dca25a51fb900a402c94c8818ad1c2789e30 for pr-77526
[INFO] extracting crate mnist 0.4.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate mnist 0.4.1 on toolchain 0d37dca25a51fb900a402c94c8818ad1c2789e30
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mnist 0.4.1
[INFO] finished tweaking crates.io crate mnist 0.4.1
[INFO] tweaked toml for crates.io crate mnist 0.4.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate mnist 0.4.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "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] a22fddac73090073bd5d991286d15aa5693e77356e2198e2bc1d06e7c7076311
[INFO] running `Command { std: "docker" "start" "-a" "a22fddac73090073bd5d991286d15aa5693e77356e2198e2bc1d06e7c7076311", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a22fddac73090073bd5d991286d15aa5693e77356e2198e2bc1d06e7c7076311", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a22fddac73090073bd5d991286d15aa5693e77356e2198e2bc1d06e7c7076311", kill_on_drop: false }`
[INFO] [stdout] a22fddac73090073bd5d991286d15aa5693e77356e2198e2bc1d06e7c7076311
[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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+0d37dca25a51fb900a402c94c8818ad1c2789e30" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 639f09889cdc60905f6e38f1c5f1b7e9ba29a16a3d7807d845abb26997143a99
[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" "639f09889cdc60905f6e38f1c5f1b7e9ba29a16a3d7807d845abb26997143a99", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.74
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]    Compiling libloading v0.6.2
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling xml-rs v0.8.3
[INFO] [stderr]    Compiling pkg-config v0.3.18
[INFO] [stderr]    Compiling nix v0.17.0
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]     Checking ppv-lite86 v0.2.8
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]     Checking scoped-tls v1.0.0
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]    Compiling matrixmultiply v0.1.15
[INFO] [stderr]    Compiling cc v1.0.58
[INFO] [stderr]     Checking rawpointer v0.1.0
[INFO] [stderr]     Checking remove_dir_all v0.5.3
[INFO] [stderr]    Compiling num-traits v0.2.12
[INFO] [stderr]    Compiling num-integer v0.1.43
[INFO] [stderr]    Compiling num-iter v0.1.41
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]     Checking dlib v0.4.2
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]     Checking wayland-sys v0.25.0
[INFO] [stderr]    Compiling xkbcommon-sys v0.7.4
[INFO] [stderr]    Compiling x11-dl v2.18.5
[INFO] [stderr]    Compiling cast v0.2.3
[INFO] [stderr]     Checking mnist v0.4.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `Vec::<T>::split_off` that must be used
[INFO] [stdout]    --> src/lib.rs:427:9
[INFO] [stdout]     |
[INFO] [stdout] 427 |         tst_img.split_off(tst_len * ROWS * COLS);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: use `.truncate()` if you don't need the other half
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Vec::<T>::split_off` that must be used
[INFO] [stdout]    --> src/lib.rs:428:9
[INFO] [stdout]     |
[INFO] [stdout] 428 |         tst_lbl.split_off(tst_len);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: use `.truncate()` if you don't need the other half
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling minifb v0.17.0
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling wayland-scanner v0.25.0
[INFO] [stderr]     Checking num v0.1.42
[INFO] [stderr]     Checking rulinalg v0.4.2
[INFO] [stderr]     Checking getrandom v0.1.14
[INFO] [stderr]     Checking raw-window-handle v0.3.3
[INFO] [stderr]     Checking rand_core v0.5.1
[INFO] [stderr]     Checking rand_chacha v0.2.2
[INFO] [stderr]     Checking xkb v0.2.1
[INFO] [stderr]     Checking rand v0.7.3
[INFO] [stderr]    Compiling wayland-client v0.25.0
[INFO] [stderr]    Compiling wayland-protocols v0.25.0
[INFO] [stderr]     Checking tempfile v3.1.0
[INFO] [stderr]     Checking wayland-commons v0.25.0
[INFO] [stderr]     Checking wayland-cursor v0.25.0
[INFO] [stdout] warning: unused return value of `Vec::<T>::split_off` that must be used
[INFO] [stdout]    --> src/lib.rs:427:9
[INFO] [stdout]     |
[INFO] [stdout] 427 |         tst_img.split_off(tst_len * ROWS * COLS);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: use `.truncate()` if you don't need the other half
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `Vec::<T>::split_off` that must be used
[INFO] [stdout]    --> src/lib.rs:428:9
[INFO] [stdout]     |
[INFO] [stdout] 428 |         tst_lbl.split_off(tst_len);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: use `.truncate()` if you don't need the other half
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 54.81s
[INFO] running `Command { std: "docker" "inspect" "639f09889cdc60905f6e38f1c5f1b7e9ba29a16a3d7807d845abb26997143a99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "639f09889cdc60905f6e38f1c5f1b7e9ba29a16a3d7807d845abb26997143a99", kill_on_drop: false }`
[INFO] [stdout] 639f09889cdc60905f6e38f1c5f1b7e9ba29a16a3d7807d845abb26997143a99