[INFO] cloning repository https://github.com/castamos/learn_rust_by_testing
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/castamos/learn_rust_by_testing" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcastamos%2Flearn_rust_by_testing", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcastamos%2Flearn_rust_by_testing'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 587cd9e21f2869191e85c687daf24781beec057a
[INFO] checking castamos/learn_rust_by_testing against 36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6 for pr-160581
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcastamos%2Flearn_rust_by_testing" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/castamos/learn_rust_by_testing
[INFO] finished tweaking git repo https://github.com/castamos/learn_rust_by_testing
[INFO] tweaked toml for git repo https://github.com/castamos/learn_rust_by_testing written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/castamos/learn_rust_by_testing on toolchain 36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/castamos/learn_rust_by_testing 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" "+36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[INFO] checking castamos/learn_rust_by_testing against 36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6 for pr-160581
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcastamos%2Flearn_rust_by_testing" "/workspace/builds/worker-1-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/castamos/learn_rust_by_testing
[INFO] finished tweaking git repo https://github.com/castamos/learn_rust_by_testing
[INFO] tweaked toml for git repo https://github.com/castamos/learn_rust_by_testing written to /workspace/builds/worker-1-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/castamos/learn_rust_by_testing on toolchain 36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/castamos/learn_rust_by_testing 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" "+36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc2/target:/opt/rustwide/target:rw,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" "-m" "1610612736" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:8683fc1fc2eb5c9ac98e0d076ab094b2ffac7f99da555d2b6a2e27f346de2ec7" "sleep" "infinity", kill_on_drop: false }`
[INFO] [stdout] e6fe464bb9fe8496553f03c6479561bcca2966a7a13a608205ca9814a0cbe20d
[INFO] running `Command { std: "docker" "start" "e6fe464bb9fe8496553f03c6479561bcca2966a7a13a608205ca9814a0cbe20d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e6fe464bb9fe8496553f03c6479561bcca2966a7a13a608205ca9814a0cbe20d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-w" "/opt/rustwide/workdir" "--user" "0:0" "e6fe464bb9fe8496553f03c6479561bcca2966a7a13a608205ca9814a0cbe20d" "/opt/rustwide/cargo-home/bin/cargo" "+36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e6fe464bb9fe8496553f03c6479561bcca2966a7a13a608205ca9814a0cbe20d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "exec" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-w" "/opt/rustwide/workdir" "--user" "0:0" "e6fe464bb9fe8496553f03c6479561bcca2966a7a13a608205ca9814a0cbe20d" "/opt/rustwide/cargo-home/bin/cargo" "+36e0a7eac2392bdd51fab6e7ff1d8c0e42d33bf6" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr]     Checking rust_by_test v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: fields `0` and `1` are never read
[INFO] [stdout]    --> tests/interior-mutability.rs:157:14
[INFO] [stdout]     |
[INFO] [stdout] 157 |         Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout]     |         ---- ^^^^^^^^^^^^^^^^  ^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         fields 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)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] help: consider changing the fields to be of unit type to suppress this warning while preserving the field numbering, or remove the fields
[INFO] [stdout]     |
[INFO] [stdout] 157 -         Cons(Rc<RefCell<i32>>, Rc<List>),
[INFO] [stdout] 157 +         Cons((), ()),
[INFO] [stdout]     |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished `dev` profile [unoptimized + debuginfo] target(s) in 0.08s
[INFO] running `Command { std: "docker" "inspect" "e6fe464bb9fe8496553f03c6479561bcca2966a7a13a608205ca9814a0cbe20d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e6fe464bb9fe8496553f03c6479561bcca2966a7a13a608205ca9814a0cbe20d", kill_on_drop: false }`
[INFO] [stdout] e6fe464bb9fe8496553f03c6479561bcca2966a7a13a608205ca9814a0cbe20d
