[INFO] fetching crate trailing_cell 0.3.0...
[INFO] checking trailing_cell-0.3.0 against beta for pr-78714
[INFO] extracting crate trailing_cell 0.3.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate trailing_cell 0.3.0 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate trailing_cell 0.3.0
[INFO] finished tweaking crates.io crate trailing_cell 0.3.0
[INFO] tweaked toml for crates.io crate trailing_cell 0.3.0 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--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-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ae08e30c422efa10d47fad3ed245c22c11e26024ce029dc59672291d59787274
[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" "ae08e30c422efa10d47fad3ed245c22c11e26024ce029dc59672291d59787274", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ae08e30c422efa10d47fad3ed245c22c11e26024ce029dc59672291d59787274", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ae08e30c422efa10d47fad3ed245c22c11e26024ce029dc59672291d59787274", kill_on_drop: false }`
[INFO] [stdout] ae08e30c422efa10d47fad3ed245c22c11e26024ce029dc59672291d59787274
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "rustops/crates-build-env@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7c1a3d13c0365f52179ecd0841fcaa8c2688e3063fdefee5507f73f56712543c
[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" "7c1a3d13c0365f52179ecd0841fcaa8c2688e3063fdefee5507f73f56712543c", kill_on_drop: false }`
[INFO] [stderr]     Checking bus v1.4.1
[INFO] [stderr]     Checking trailing_cell v0.3.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused return value of `std::result::Result::<T, E>::is_ok` that must be used
[INFO] [stdout]   --> src/tests.rs:77:9
[INFO] [stdout]    |
[INFO] [stdout] 77 |         h.join().is_ok();
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]    = note: if you intended to assert that this is ok, consider `.unwrap()` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::result::Result::<T, E>::is_ok` that must be used
[INFO] [stdout]    --> src/tests.rs:103:5
[INFO] [stdout]     |
[INFO] [stdout] 103 |     h1.join().is_ok();
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to assert that this is ok, consider `.unwrap()` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused return value of `std::result::Result::<T, E>::is_ok` that must be used
[INFO] [stdout]    --> src/tests.rs:104:5
[INFO] [stdout]     |
[INFO] [stdout] 104 |     h2.join().is_ok();
[INFO] [stdout]     |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: if you intended to assert that this is ok, consider `.unwrap()` instead
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.08s
[INFO] running `Command { std: "docker" "inspect" "7c1a3d13c0365f52179ecd0841fcaa8c2688e3063fdefee5507f73f56712543c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7c1a3d13c0365f52179ecd0841fcaa8c2688e3063fdefee5507f73f56712543c", kill_on_drop: false }`
[INFO] [stdout] 7c1a3d13c0365f52179ecd0841fcaa8c2688e3063fdefee5507f73f56712543c