[INFO] updating cached repository https://github.com/mrbkap/rust_guessing_game
[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] 0e2c3f4c9cabb3231abd78a63797520e4bec770e
[INFO] checking mrbkap/rust_guessing_game against master#8ac1525e091d3db28e67adcbbd6db1e1deaa37fb for pr-73323
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmrbkap%2Frust_guessing_game" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mrbkap/rust_guessing_game on toolchain 8ac1525e091d3db28e67adcbbd6db1e1deaa37fb
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/mrbkap/rust_guessing_game
[INFO] finished tweaking git repo https://github.com/mrbkap/rust_guessing_game
[INFO] tweaked toml for git repo https://github.com/mrbkap/rust_guessing_game written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/mrbkap/rust_guessing_game already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] error: the lock file /workspace/builds/worker-6/source/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] [stderr] If you want to try to generate the lock file without accessing the network, use the --offline flag.
[INFO] the lockfile is outdated, regenerating it
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "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] 7634d8a37a10ac97d75a6c2ebbdcadf019d92417edce97beeb923175fd52e8a0
[INFO] running `Command { std: "docker" "start" "-a" "7634d8a37a10ac97d75a6c2ebbdcadf019d92417edce97beeb923175fd52e8a0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7634d8a37a10ac97d75a6c2ebbdcadf019d92417edce97beeb923175fd52e8a0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7634d8a37a10ac97d75a6c2ebbdcadf019d92417edce97beeb923175fd52e8a0", kill_on_drop: false }`
[INFO] [stdout] 7634d8a37a10ac97d75a6c2ebbdcadf019d92417edce97beeb923175fd52e8a0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:d9fbb4e2287ab3795bdefaf705efb7541a8875c13bce71e067d6b01dc5ed759b" "/opt/rustwide/cargo-home/bin/cargo" "+8ac1525e091d3db28e67adcbbd6db1e1deaa37fb" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e1adb3c2902592b5387f102517e1fc2246edf0f4b11eead8731d758064cdd476
[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" "e1adb3c2902592b5387f102517e1fc2246edf0f4b11eead8731d758064cdd476", kill_on_drop: false }`
[INFO] [stderr]     Checking guessing_game v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `Read`
[INFO] [stdout]  --> solver/solver.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{Read,Write};
[INFO] [stdout]   |               ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `Read`
[INFO] [stdout]  --> solver/solver.rs:2:15
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::io::{Read,Write};
[INFO] [stdout]   |               ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.84s
[INFO] running `Command { std: "docker" "inspect" "e1adb3c2902592b5387f102517e1fc2246edf0f4b11eead8731d758064cdd476", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e1adb3c2902592b5387f102517e1fc2246edf0f4b11eead8731d758064cdd476", kill_on_drop: false }`
[INFO] [stdout] e1adb3c2902592b5387f102517e1fc2246edf0f4b11eead8731d758064cdd476