[INFO] cloning repository https://github.com/Jonwod/ping_pong
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Jonwod/ping_pong" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJonwod%2Fping_pong", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJonwod%2Fping_pong'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 50a757fe8f53d3375033a2d19b5266a73e9958a3
[INFO] checking Jonwod/ping_pong against try#b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f for pr-76104
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FJonwod%2Fping_pong" "/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/Jonwod/ping_pong on toolchain b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Jonwod/ping_pong
[INFO] finished tweaking git repo https://github.com/Jonwod/ping_pong
[INFO] tweaked toml for git repo https://github.com/Jonwod/ping_pong written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/Jonwod/ping_pong already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e44702299f598aa229ce51d8e4a6490dc3f0924c2c18276e8fd0225d476b6f07
[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" "e44702299f598aa229ce51d8e4a6490dc3f0924c2c18276e8fd0225d476b6f07", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e44702299f598aa229ce51d8e4a6490dc3f0924c2c18276e8fd0225d476b6f07", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e44702299f598aa229ce51d8e4a6490dc3f0924c2c18276e8fd0225d476b6f07", kill_on_drop: false }`
[INFO] [stdout] e44702299f598aa229ce51d8e4a6490dc3f0924c2c18276e8fd0225d476b6f07
[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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 59a4d838db898bb60b9eb11649f482c22a6ef3604f17ceb2753e61072f55251e
[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" "59a4d838db898bb60b9eb11649f482c22a6ef3604f17ceb2753e61072f55251e", kill_on_drop: false }`
[INFO] [stderr]     Checking ping_pong v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]  --> src/main.rs:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let mut buff = &mut [0 as u8];
[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:8:9
[INFO] [stdout]   |
[INFO] [stdout] 8 |     let mut buff = &mut [0 as u8];
[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: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.23s
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "59a4d838db898bb60b9eb11649f482c22a6ef3604f17ceb2753e61072f55251e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "59a4d838db898bb60b9eb11649f482c22a6ef3604f17ceb2753e61072f55251e", kill_on_drop: false }`
[INFO] [stdout] 59a4d838db898bb60b9eb11649f482c22a6ef3604f17ceb2753e61072f55251e