[INFO] updating cached repository https://github.com/intrepion/example-x-rust-x-rustbyexample-com-x-std-option
[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] 48e8a4eda3c5524b42a376dcad30a64cb38cdf12
[INFO] checking intrepion/example-x-rust-x-rustbyexample-com-x-std-option against try#6024cfef3a82f9a7688f07054f1650081bad3af5 for pr-74130
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fintrepion%2Fexample-x-rust-x-rustbyexample-com-x-std-option" "/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/intrepion/example-x-rust-x-rustbyexample-com-x-std-option on toolchain 6024cfef3a82f9a7688f07054f1650081bad3af5
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6024cfef3a82f9a7688f07054f1650081bad3af5" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/intrepion/example-x-rust-x-rustbyexample-com-x-std-option
[INFO] finished tweaking git repo https://github.com/intrepion/example-x-rust-x-rustbyexample-com-x-std-option
[INFO] tweaked toml for git repo https://github.com/intrepion/example-x-rust-x-rustbyexample-com-x-std-option written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/intrepion/example-x-rust-x-rustbyexample-com-x-std-option already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6024cfef3a82f9a7688f07054f1650081bad3af5" "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" "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@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+6024cfef3a82f9a7688f07054f1650081bad3af5" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 31bf2dd2e0a365ba38122ca2d6dbb975be345e0500a046731b0c70334813076c
[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" "31bf2dd2e0a365ba38122ca2d6dbb975be345e0500a046731b0c70334813076c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "31bf2dd2e0a365ba38122ca2d6dbb975be345e0500a046731b0c70334813076c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "31bf2dd2e0a365ba38122ca2d6dbb975be345e0500a046731b0c70334813076c", kill_on_drop: false }`
[INFO] [stdout] 31bf2dd2e0a365ba38122ca2d6dbb975be345e0500a046731b0c70334813076c
[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" "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@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+6024cfef3a82f9a7688f07054f1650081bad3af5" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1dfef6197c91c5d2faa9475bf0665dd8559960e670ff100748d52f986eb4fdea
[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" "1dfef6197c91c5d2faa9475bf0665dd8559960e670ff100748d52f986eb4fdea", kill_on_drop: false }`
[INFO] [stderr]     Checking example-x-rust-x-rustbyexample-com-x-std-option v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused variable: `none`
[INFO] [stdout]   --> src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let none: Option<i32> = None;
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_none`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `none`
[INFO] [stdout]   --> src/main.rs:28:9
[INFO] [stdout]    |
[INFO] [stdout] 28 |     let none: Option<i32> = None;
[INFO] [stdout]    |         ^^^^ help: if this is intentional, prefix it with an underscore: `_none`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_variables)]` 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 0.19s
[INFO] running `Command { std: "docker" "inspect" "1dfef6197c91c5d2faa9475bf0665dd8559960e670ff100748d52f986eb4fdea", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1dfef6197c91c5d2faa9475bf0665dd8559960e670ff100748d52f986eb4fdea", kill_on_drop: false }`
[INFO] [stdout] 1dfef6197c91c5d2faa9475bf0665dd8559960e670ff100748d52f986eb4fdea