[INFO] fetching crate file_diff 1.0.0...
[INFO] checking file_diff-1.0.0 against try#b2f80f6008cdafc35b4472bd46afa16cc6b0cd63 for pr-79470
[INFO] extracting crate file_diff 1.0.0 into /workspace/builds/worker-10/source
[INFO] validating manifest of crates.io crate file_diff 1.0.0 on toolchain b2f80f6008cdafc35b4472bd46afa16cc6b0cd63
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate file_diff 1.0.0
[INFO] finished tweaking crates.io crate file_diff 1.0.0
[INFO] tweaked toml for crates.io crate file_diff 1.0.0 written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d8603eaf6ad306207482b7b80db1f57fd6a0feda562f10463bb49e5dfb79a2db
[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" "d8603eaf6ad306207482b7b80db1f57fd6a0feda562f10463bb49e5dfb79a2db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d8603eaf6ad306207482b7b80db1f57fd6a0feda562f10463bb49e5dfb79a2db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d8603eaf6ad306207482b7b80db1f57fd6a0feda562f10463bb49e5dfb79a2db", kill_on_drop: false }`
[INFO] [stdout] d8603eaf6ad306207482b7b80db1f57fd6a0feda562f10463bb49e5dfb79a2db
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f52e2ebdef6da3a7aa38d15d3b241f40aa6ba127bced3d3b1c825f445322a55e
[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" "f52e2ebdef6da3a7aa38d15d3b241f40aa6ba127bced3d3b1c825f445322a55e", kill_on_drop: false }`
[INFO] [stderr]     Checking file_diff v1.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/lib.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let mut buff1 : &mut [u8] = &mut [0; 1024];
[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/lib.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let mut buff2 : &mut [u8] = &mut [0; 1024];
[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/lib.rs:49:9
[INFO] [stdout]    |
[INFO] [stdout] 49 |     let mut buff1 : &mut [u8] = &mut [0; 1024];
[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/lib.rs:50:9
[INFO] [stdout]    |
[INFO] [stdout] 50 |     let mut buff2 : &mut [u8] = &mut [0; 1024];
[INFO] [stdout]    |         ----^^^^^
[INFO] [stdout]    |         |
[INFO] [stdout]    |         help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.36s
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "f52e2ebdef6da3a7aa38d15d3b241f40aa6ba127bced3d3b1c825f445322a55e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f52e2ebdef6da3a7aa38d15d3b241f40aa6ba127bced3d3b1c825f445322a55e", kill_on_drop: false }`
[INFO] [stdout] f52e2ebdef6da3a7aa38d15d3b241f40aa6ba127bced3d3b1c825f445322a55e