[INFO] cloning repository https://github.com/tynr426/regex_learn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tynr426/regex_learn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftynr426%2Fregex_learn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftynr426%2Fregex_learn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] f59ec04f199a67c8bdaebe162b45a52c8b8e4cb5
[INFO] checking tynr426/regex_learn against master#7dc9ff5c629753b6930ecfe9a0446538b8e25fb7 for pr-85387
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftynr426%2Fregex_learn" "/workspace/builds/worker-7/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tynr426/regex_learn on toolchain 7dc9ff5c629753b6930ecfe9a0446538b8e25fb7
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+7dc9ff5c629753b6930ecfe9a0446538b8e25fb7" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/tynr426/regex_learn
[INFO] finished tweaking git repo https://github.com/tynr426/regex_learn
[INFO] tweaked toml for git repo https://github.com/tynr426/regex_learn written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] crate git repo https://github.com/tynr426/regex_learn already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+7dc9ff5c629753b6930ecfe9a0446538b8e25fb7" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+7dc9ff5c629753b6930ecfe9a0446538b8e25fb7" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 2e5d9d07b911d6d84eb2da31599124098be9edd0d32cd7aea0d6baeef2e9867f
[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" "2e5d9d07b911d6d84eb2da31599124098be9edd0d32cd7aea0d6baeef2e9867f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "2e5d9d07b911d6d84eb2da31599124098be9edd0d32cd7aea0d6baeef2e9867f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2e5d9d07b911d6d84eb2da31599124098be9edd0d32cd7aea0d6baeef2e9867f", kill_on_drop: false }`
[INFO] [stdout] 2e5d9d07b911d6d84eb2da31599124098be9edd0d32cd7aea0d6baeef2e9867f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "+7dc9ff5c629753b6930ecfe9a0446538b8e25fb7" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 2710b32a489c12fc538b2a6cd251a622b269d449a6f82a5d028ba6e43f3232d7
[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" "2710b32a489c12fc538b2a6cd251a622b269d449a6f82a5d028ba6e43f3232d7", kill_on_drop: false }`
[INFO] [stderr]     Checking regex v1.3.1
[INFO] [stderr]     Checking regex_learn v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let mut str2 = "{xy:7,xx:\"kk\",\"key\":\"bbb\"}";
[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:55:9
[INFO] [stdout]    |
[INFO] [stdout] 55 |     let mut str2 = "{xy:7,xx:\"kk\",\"key\":\"bbb\"}";
[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] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.81s
[INFO] running `Command { std: "docker" "inspect" "2710b32a489c12fc538b2a6cd251a622b269d449a6f82a5d028ba6e43f3232d7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2710b32a489c12fc538b2a6cd251a622b269d449a6f82a5d028ba6e43f3232d7", kill_on_drop: false }`
[INFO] [stdout] 2710b32a489c12fc538b2a6cd251a622b269d449a6f82a5d028ba6e43f3232d7