[INFO] cloning repository https://github.com/andozw/rust_guess
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/andozw/rust_guess" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fandozw%2Frust_guess", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fandozw%2Frust_guess'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bb4b5f6bf0ee7cfd2a75dc84000a6d98b3afdcf4
[INFO] building andozw/rust_guess against master#11663cd3bfefef7d34e8f0892c250bf698049392+rustflags=-Dtail-expr-drop-order for pr-134523
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fandozw%2Frust_guess" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/andozw/rust_guess on toolchain 11663cd3bfefef7d34e8f0892c250bf698049392
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/andozw/rust_guess
[INFO] finished tweaking git repo https://github.com/andozw/rust_guess
[INFO] tweaked toml for git repo https://github.com/andozw/rust_guess written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/andozw/rust_guess already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "fetch" "--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-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6b0d3ddff54628eea0d1009981f828e879773340782f58dbb43665745568435e
[INFO] running `Command { std: "docker" "start" "-a" "6b0d3ddff54628eea0d1009981f828e879773340782f58dbb43665745568435e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6b0d3ddff54628eea0d1009981f828e879773340782f58dbb43665745568435e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6b0d3ddff54628eea0d1009981f828e879773340782f58dbb43665745568435e", kill_on_drop: false }`
[INFO] [stdout] 6b0d3ddff54628eea0d1009981f828e879773340782f58dbb43665745568435e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 42507268cc48952aeeb1434223bc14a9c19495b23f761e358e0bb0f65eae87e6
[INFO] running `Command { std: "docker" "start" "-a" "42507268cc48952aeeb1434223bc14a9c19495b23f761e358e0bb0f65eae87e6", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.112
[INFO] [stderr]    Compiling ppv-lite86 v0.2.15
[INFO] [stderr]    Compiling bytes v1.1.0
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling rand v0.8.4
[INFO] [stderr]    Compiling rust_guess v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> src/main.rs:7:10
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout]   |     ---- ^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Cons((), RefCell<Rc<List>>),
[INFO] [stdout]   |          ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 1.58s
[INFO] running `Command { std: "docker" "inspect" "42507268cc48952aeeb1434223bc14a9c19495b23f761e358e0bb0f65eae87e6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "42507268cc48952aeeb1434223bc14a9c19495b23f761e358e0bb0f65eae87e6", kill_on_drop: false }`
[INFO] [stdout] 42507268cc48952aeeb1434223bc14a9c19495b23f761e358e0bb0f65eae87e6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/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 -Dtail-expr-drop-order" "-e" "RUSTDOCFLAGS=--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:f3a9d4ad9d972b27faf3965f35b62e55ba32bbce8f20bc8fe909558a86702fde" "/opt/rustwide/cargo-home/bin/cargo" "+11663cd3bfefef7d34e8f0892c250bf698049392" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b397b736f3ab2e3e494eeaf1ed8802e24765410a05d0a1e11799735cc88aec90
[INFO] running `Command { std: "docker" "start" "-a" "b397b736f3ab2e3e494eeaf1ed8802e24765410a05d0a1e11799735cc88aec90", kill_on_drop: false }`
[INFO] [stderr]    Compiling rust_guess v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: field `0` is never read
[INFO] [stdout]  --> src/main.rs:7:10
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Cons(i32, RefCell<Rc<List>>),
[INFO] [stdout]   |     ---- ^^^
[INFO] [stdout]   |     |
[INFO] [stdout]   |     field in this variant
[INFO] [stdout]   |
[INFO] [stdout]   = note: `List` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]   = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] help: consider changing the field to be of unit type to suppress this warning while preserving the field numbering, or remove the field
[INFO] [stdout]   |
[INFO] [stdout] 7 |     Cons((), RefCell<Rc<List>>),
[INFO] [stdout]   |          ~~
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `test` profile [unoptimized + debuginfo] target(s) in 0.34s
[INFO] running `Command { std: "docker" "inspect" "b397b736f3ab2e3e494eeaf1ed8802e24765410a05d0a1e11799735cc88aec90", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b397b736f3ab2e3e494eeaf1ed8802e24765410a05d0a1e11799735cc88aec90", kill_on_drop: false }`
[INFO] [stdout] b397b736f3ab2e3e494eeaf1ed8802e24765410a05d0a1e11799735cc88aec90