[INFO] crate mnist 0.4.0 is already in cache
[INFO] checking mnist-0.4.0 against master#ba72b15666b2491415aec703a02c2364fe5e2790 for pr-71140
[INFO] extracting crate mnist 0.4.0 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate mnist 0.4.0 on toolchain ba72b15666b2491415aec703a02c2364fe5e2790
[INFO] running `"/workspace/cargo-home/bin/cargo" "+ba72b15666b2491415aec703a02c2364fe5e2790" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate mnist 0.4.0
[INFO] finished tweaking crates.io crate mnist 0.4.0
[INFO] tweaked toml for crates.io crate mnist 0.4.0 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+ba72b15666b2491415aec703a02c2364fe5e2790" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+ba72b15666b2491415aec703a02c2364fe5e2790" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+ba72b15666b2491415aec703a02c2364fe5e2790" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] e6765a49e3ab7545293678a72972e9c7b74792d74055f447832043297fc7a7aa
[INFO] running `"docker" "start" "-a" "e6765a49e3ab7545293678a72972e9c7b74792d74055f447832043297fc7a7aa"`
[INFO] [stderr]     Checking mnist v0.4.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused return value of `std::vec::Vec::<T>::split_off` that must be used
[INFO] [stderr]    --> src/lib.rs:358:9
[INFO] [stderr]     |
[INFO] [stderr] 358 |         tst_img.split_off(tst_len * ROWS * COLS);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]     = note: use `.truncate()` if you don't need the other half
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::vec::Vec::<T>::split_off` that must be used
[INFO] [stderr]    --> src/lib.rs:359:9
[INFO] [stderr]     |
[INFO] [stderr] 359 |         tst_lbl.split_off(tst_len);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: use `.truncate()` if you don't need the other half
[INFO] [stderr] 
[INFO] [stderr] warning: 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::vec::Vec::<T>::split_off` that must be used
[INFO] [stderr]    --> src/lib.rs:358:9
[INFO] [stderr]     |
[INFO] [stderr] 358 |         tst_img.split_off(tst_len * ROWS * COLS);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]     = note: use `.truncate()` if you don't need the other half
[INFO] [stderr] 
[INFO] [stderr] warning: unused return value of `std::vec::Vec::<T>::split_off` that must be used
[INFO] [stderr]    --> src/lib.rs:359:9
[INFO] [stderr]     |
[INFO] [stderr] 359 |         tst_lbl.split_off(tst_len);
[INFO] [stderr]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: use `.truncate()` if you don't need the other half
[INFO] [stderr] 
[INFO] [stderr] warning: 2 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.18s
[INFO] running `"docker" "inspect" "e6765a49e3ab7545293678a72972e9c7b74792d74055f447832043297fc7a7aa"`
[INFO] running `"docker" "rm" "-f" "e6765a49e3ab7545293678a72972e9c7b74792d74055f447832043297fc7a7aa"`
[INFO] [stdout] e6765a49e3ab7545293678a72972e9c7b74792d74055f447832043297fc7a7aa