[INFO] cloning repository https://github.com/xiaanyin/mnist
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/xiaanyin/mnist" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaanyin%2Fmnist", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaanyin%2Fmnist'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9275c45efac197365e61b0c7b49c2a09790690e2
[INFO] building xiaanyin/mnist against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fxiaanyin%2Fmnist" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/xiaanyin/mnist on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/xiaanyin/mnist
[INFO] finished tweaking git repo https://github.com/xiaanyin/mnist
[INFO] tweaked toml for git repo https://github.com/xiaanyin/mnist written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/xiaanyin/mnist already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fdc4e66e899ae9090ecc841b5a017db8349694faa16986585de0ca88fa54b653
[INFO] running `Command { std: "docker" "start" "-a" "fdc4e66e899ae9090ecc841b5a017db8349694faa16986585de0ca88fa54b653", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fdc4e66e899ae9090ecc841b5a017db8349694faa16986585de0ca88fa54b653", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fdc4e66e899ae9090ecc841b5a017db8349694faa16986585de0ca88fa54b653", kill_on_drop: false }`
[INFO] [stdout] fdc4e66e899ae9090ecc841b5a017db8349694faa16986585de0ca88fa54b653
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d94a05206351fa78cdb5cad39d1696f9b4262ecb454dd4a448e3ebed0fe74de5
[INFO] running `Command { std: "docker" "start" "-a" "d94a05206351fa78cdb5cad39d1696f9b4262ecb454dd4a448e3ebed0fe74de5", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling getrandom v0.1.12
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling ppv-lite86 v0.2.5
[INFO] [stderr]    Compiling c2-chacha v0.2.2
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling rand v0.7.2
[INFO] [stderr]    Compiling mnist v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:163:17
[INFO] [stdout]     |
[INFO] [stdout] 163 |             let mut cell = &mut output_layer.cells_vec[index];
[INFO] [stdout]     |                 ----^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:203:21
[INFO] [stdout]     |
[INFO] [stdout] 203 |                 let mut cell = &mut pre_layer.cells_vec[update_src.0];
[INFO] [stdout]     |                     ----^^^^
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:213:17
[INFO] [stdout]     |
[INFO] [stdout] 213 |             let mut cell: &mut NeuralCell = &mut layer.cells_vec[index_cell];
[INFO] [stdout]     |                 ----^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 2.97s
[INFO] running `Command { std: "docker" "inspect" "d94a05206351fa78cdb5cad39d1696f9b4262ecb454dd4a448e3ebed0fe74de5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d94a05206351fa78cdb5cad39d1696f9b4262ecb454dd4a448e3ebed0fe74de5", kill_on_drop: false }`
[INFO] [stdout] d94a05206351fa78cdb5cad39d1696f9b4262ecb454dd4a448e3ebed0fe74de5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] af5190fc0cffe2632fa0e531c887b6e371a3b55c1348a066115dbd16eee8f167
[INFO] running `Command { std: "docker" "start" "-a" "af5190fc0cffe2632fa0e531c887b6e371a3b55c1348a066115dbd16eee8f167", kill_on_drop: false }`
[INFO] [stderr]    Compiling mnist v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:163:17
[INFO] [stdout]     |
[INFO] [stdout] 163 |             let mut cell = &mut output_layer.cells_vec[index];
[INFO] [stdout]     |                 ----^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:203:21
[INFO] [stdout]     |
[INFO] [stdout] 203 |                 let mut cell = &mut pre_layer.cells_vec[update_src.0];
[INFO] [stdout]     |                     ----^^^^
[INFO] [stdout]     |                     |
[INFO] [stdout]     |                     help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/core.rs:213:17
[INFO] [stdout]     |
[INFO] [stdout] 213 |             let mut cell: &mut NeuralCell = &mut layer.cells_vec[index_cell];
[INFO] [stdout]     |                 ----^^^^
[INFO] [stdout]     |                 |
[INFO] [stdout]     |                 help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.35s
[INFO] running `Command { std: "docker" "inspect" "af5190fc0cffe2632fa0e531c887b6e371a3b55c1348a066115dbd16eee8f167", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "af5190fc0cffe2632fa0e531c887b6e371a3b55c1348a066115dbd16eee8f167", kill_on_drop: false }`
[INFO] [stdout] af5190fc0cffe2632fa0e531c887b6e371a3b55c1348a066115dbd16eee8f167