[INFO] cloning repository https://github.com/Bkindmonk/RustPractice
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Bkindmonk/RustPractice" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBkindmonk%2FRustPractice", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBkindmonk%2FRustPractice'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] dddc1c842ad316fb93f1f4a3a9741aea4ff490c9
[INFO] checking Bkindmonk/RustPractice against beta for pr-78714
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FBkindmonk%2FRustPractice" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Bkindmonk/RustPractice on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Bkindmonk/RustPractice
[INFO] finished tweaking git repo https://github.com/Bkindmonk/RustPractice
[INFO] tweaked toml for git repo https://github.com/Bkindmonk/RustPractice written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/Bkindmonk/RustPractice already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1b644e478bc9a53d0d3c5bc5b00eca50241f267fd5fa8fce7ad7de6263ba8d57
[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" "1b644e478bc9a53d0d3c5bc5b00eca50241f267fd5fa8fce7ad7de6263ba8d57", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1b644e478bc9a53d0d3c5bc5b00eca50241f267fd5fa8fce7ad7de6263ba8d57", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1b644e478bc9a53d0d3c5bc5b00eca50241f267fd5fa8fce7ad7de6263ba8d57", kill_on_drop: false }`
[INFO] [stdout] 1b644e478bc9a53d0d3c5bc5b00eca50241f267fd5fa8fce7ad7de6263ba8d57
[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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3e2a254b52292b2749d953af85bdf933df6c44e92b206173f0a718b135620789
[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" "3e2a254b52292b2749d953af85bdf933df6c44e92b206173f0a718b135620789", kill_on_drop: false }`
[INFO] [stderr]     Checking mergesort v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:91:13
[INFO] [stdout]    |
[INFO] [stdout] 91 |         let mut realhalves = (*real).split_at_mut(halflength);
[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/main.rs:92:13
[INFO] [stdout]    |
[INFO] [stdout] 92 |         let mut scratchhalves = (*scratch).split_at_mut(halflength);
[INFO] [stdout]    |             ----^^^^^^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:91:13
[INFO] [stdout]    |
[INFO] [stdout] 91 |         let mut realhalves = (*real).split_at_mut(halflength);
[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/main.rs:92:13
[INFO] [stdout]    |
[INFO] [stdout] 92 |         let mut scratchhalves = (*scratch).split_at_mut(halflength);
[INFO] [stdout]    |             ----^^^^^^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.70s
[INFO] running `Command { std: "docker" "inspect" "3e2a254b52292b2749d953af85bdf933df6c44e92b206173f0a718b135620789", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3e2a254b52292b2749d953af85bdf933df6c44e92b206173f0a718b135620789", kill_on_drop: false }`
[INFO] [stdout] 3e2a254b52292b2749d953af85bdf933df6c44e92b206173f0a718b135620789