[INFO] cloning repository https://github.com/b-m-f/rust_playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/b-m-f/rust_playground" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fb-m-f%2Frust_playground", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fb-m-f%2Frust_playground'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] fd5f5c1e312db99abdf4b07d809f0735db153586
[INFO] checking b-m-f/rust_playground against try#6f8a6450478f69b8510c8976ab6c2a70b3b0e47c for pr-84920
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fb-m-f%2Frust_playground" "/workspace/builds/worker-14/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-14/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/b-m-f/rust_playground on toolchain 6f8a6450478f69b8510c8976ab6c2a70b3b0e47c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/b-m-f/rust_playground
[INFO] finished tweaking git repo https://github.com/b-m-f/rust_playground
[INFO] tweaked toml for git repo https://github.com/b-m-f/rust_playground written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] crate git repo https://github.com/b-m-f/rust_playground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d4112e88d18cfe98a6a9db07dd5bdf5a50c6cc842797885c0820b101c9bb2ac6
[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" "d4112e88d18cfe98a6a9db07dd5bdf5a50c6cc842797885c0820b101c9bb2ac6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d4112e88d18cfe98a6a9db07dd5bdf5a50c6cc842797885c0820b101c9bb2ac6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d4112e88d18cfe98a6a9db07dd5bdf5a50c6cc842797885c0820b101c9bb2ac6", kill_on_drop: false }`
[INFO] [stdout] d4112e88d18cfe98a6a9db07dd5bdf5a50c6cc842797885c0820b101c9bb2ac6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+6f8a6450478f69b8510c8976ab6c2a70b3b0e47c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 40ad08092371b03315c3f8d69ab8ce69b302b08bc77c331d9e51844ded27dfcb
[INFO] running `Command { std: "docker" "start" "-a" "40ad08092371b03315c3f8d69ab8ce69b302b08bc77c331d9e51844ded27dfcb", kill_on_drop: false }`
[INFO] [stderr]     Checking term v0.4.4
[INFO] [stderr]     Checking fs_examples v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: function is never used: `factorial_recursive`
[INFO] [stdout]  --> src/math.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn factorial_recursive(n: i64) -> i64 {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `factorial`
[INFO] [stdout]  --> src/math.rs:6:8
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub fn factorial (n: i64) -> i64 {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `factorial_recursive`
[INFO] [stdout]  --> src/math.rs:1:8
[INFO] [stdout]   |
[INFO] [stdout] 1 | pub fn factorial_recursive(n: i64) -> i64 {
[INFO] [stdout]   |        ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `factorial`
[INFO] [stdout]  --> src/math.rs:6:8
[INFO] [stdout]   |
[INFO] [stdout] 6 | pub fn factorial (n: i64) -> i64 {
[INFO] [stdout]   |        ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.06s
[INFO] running `Command { std: "docker" "inspect" "40ad08092371b03315c3f8d69ab8ce69b302b08bc77c331d9e51844ded27dfcb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "40ad08092371b03315c3f8d69ab8ce69b302b08bc77c331d9e51844ded27dfcb", kill_on_drop: false }`
[INFO] [stdout] 40ad08092371b03315c3f8d69ab8ce69b302b08bc77c331d9e51844ded27dfcb