[INFO] updating cached repository https://github.com/ravendyg/rust-playground
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f0fbaf1c751f3fbfd6b05d9779721bfa5fc7f25f
[INFO] testing ravendyg/rust-playground against master#8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e for pr-74409
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fravendyg%2Frust-playground" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ravendyg/rust-playground on toolchain 8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/ravendyg/rust-playground
[INFO] finished tweaking git repo https://github.com/ravendyg/rust-playground
[INFO] tweaked toml for git repo https://github.com/ravendyg/rust-playground written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/ravendyg/rust-playground already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "metadata" "--no-deps" "--format-version=1", 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] 370e3c634913a94b9f2b94664d6fdd8ec5325bf110f8a5a468ca8cbd7af60103
[INFO] running `Command { std: "docker" "start" "-a" "370e3c634913a94b9f2b94664d6fdd8ec5325bf110f8a5a468ca8cbd7af60103", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "370e3c634913a94b9f2b94664d6fdd8ec5325bf110f8a5a468ca8cbd7af60103", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "370e3c634913a94b9f2b94664d6fdd8ec5325bf110f8a5a468ca8cbd7af60103", kill_on_drop: false }`
[INFO] [stdout] 370e3c634913a94b9f2b94664d6fdd8ec5325bf110f8a5a468ca8cbd7af60103
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4a6863e4d0cbf9f504d867b502e8f43ce48d4c25244c234a204c36dfe9c1f366
[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" "4a6863e4d0cbf9f504d867b502e8f43ce48d4c25244c234a204c36dfe9c1f366", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.18
[INFO] [stderr]    Compiling rand v0.3.15
[INFO] [stderr]    Compiling guessing v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:60:7
[INFO] [stdout]    |
[INFO] [stdout] 60 |   let x: Option<i32> = Option::Some(5);
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `q`
[INFO] [stdout]   --> src/main.rs:62:7
[INFO] [stdout]    |
[INFO] [stdout] 62 |   let q: Option<f64> = Option::Some(5f64);
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_q`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/main.rs:71:7
[INFO] [stdout]    |
[INFO] [stdout] 71 |   let b = 10;
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `None`
[INFO] [stdout]   --> src/main.rs:49:3
[INFO] [stdout]    |
[INFO] [stdout] 49 |   None
[INFO] [stdout]    |   ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/main.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 | enum Result<T, E> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.92s
[INFO] running `Command { std: "docker" "inspect" "4a6863e4d0cbf9f504d867b502e8f43ce48d4c25244c234a204c36dfe9c1f366", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a6863e4d0cbf9f504d867b502e8f43ce48d4c25244c234a204c36dfe9c1f366", kill_on_drop: false }`
[INFO] [stdout] 4a6863e4d0cbf9f504d867b502e8f43ce48d4c25244c234a204c36dfe9c1f366
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 85826c18b8b85ee357638d2092198edcd238a4a57dc274eeda6be0ece9e07925
[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" "85826c18b8b85ee357638d2092198edcd238a4a57dc274eeda6be0ece9e07925", kill_on_drop: false }`
[INFO] [stderr]    Compiling guessing v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `x`
[INFO] [stdout]   --> src/main.rs:60:7
[INFO] [stdout]    |
[INFO] [stdout] 60 |   let x: Option<i32> = Option::Some(5);
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `q`
[INFO] [stdout]   --> src/main.rs:62:7
[INFO] [stdout]    |
[INFO] [stdout] 62 |   let q: Option<f64> = Option::Some(5f64);
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_q`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `b`
[INFO] [stdout]   --> src/main.rs:71:7
[INFO] [stdout]    |
[INFO] [stdout] 71 |   let b = 10;
[INFO] [stdout]    |       ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variant is never constructed: `None`
[INFO] [stdout]   --> src/main.rs:49:3
[INFO] [stdout]    |
[INFO] [stdout] 49 |   None
[INFO] [stdout]    |   ^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: enum is never used: `Result`
[INFO] [stdout]   --> src/main.rs:53:6
[INFO] [stdout]    |
[INFO] [stdout] 53 | enum Result<T, E> {
[INFO] [stdout]    |      ^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 5 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.60s
[INFO] running `Command { std: "docker" "inspect" "85826c18b8b85ee357638d2092198edcd238a4a57dc274eeda6be0ece9e07925", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "85826c18b8b85ee357638d2092198edcd238a4a57dc274eeda6be0ece9e07925", kill_on_drop: false }`
[INFO] [stdout] 85826c18b8b85ee357638d2092198edcd238a4a57dc274eeda6be0ece9e07925
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+8534be72fc3b9c5f2f2dc4e4ee7b651a008e9a3e" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 10a3c46570e29ca04a7dbd7c835de316e54a700a2aa63d1c23f9004094039827
[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" "10a3c46570e29ca04a7dbd7c835de316e54a700a2aa63d1c23f9004094039827", kill_on_drop: false }`
[INFO] [stderr] warning: unused variable: `x`
[INFO] [stderr]   --> src/main.rs:60:7
[INFO] [stderr]    |
[INFO] [stderr] 60 |   let x: Option<i32> = Option::Some(5);
[INFO] [stderr]    |       ^ help: if this is intentional, prefix it with an underscore: `_x`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `q`
[INFO] [stderr]   --> src/main.rs:62:7
[INFO] [stderr]    |
[INFO] [stderr] 62 |   let q: Option<f64> = Option::Some(5f64);
[INFO] [stderr]    |       ^ help: if this is intentional, prefix it with an underscore: `_q`
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `b`
[INFO] [stderr]   --> src/main.rs:71:7
[INFO] [stderr]    |
[INFO] [stderr] 71 |   let b = 10;
[INFO] [stderr]    |       ^ help: if this is intentional, prefix it with an underscore: `_b`
[INFO] [stderr] 
[INFO] [stderr] warning: variant is never constructed: `None`
[INFO] [stderr]   --> src/main.rs:49:3
[INFO] [stderr]    |
[INFO] [stderr] 49 |   None
[INFO] [stderr]    |   ^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: enum is never used: `Result`
[INFO] [stderr]   --> src/main.rs:53:6
[INFO] [stderr]    |
[INFO] [stderr] 53 | enum Result<T, E> {
[INFO] [stderr]    |      ^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: 5 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.02s
[INFO] [stdout] 
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/guessing-bcbb23439516e264
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "10a3c46570e29ca04a7dbd7c835de316e54a700a2aa63d1c23f9004094039827", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "10a3c46570e29ca04a7dbd7c835de316e54a700a2aa63d1c23f9004094039827", kill_on_drop: false }`
[INFO] [stdout] 10a3c46570e29ca04a7dbd7c835de316e54a700a2aa63d1c23f9004094039827