[INFO] fetching crate trailing_cell 0.3.0...
[INFO] checking trailing_cell-0.3.0 against try#b2f80f6008cdafc35b4472bd46afa16cc6b0cd63 for pr-79470
[INFO] extracting crate trailing_cell 0.3.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate trailing_cell 0.3.0 on toolchain b2f80f6008cdafc35b4472bd46afa16cc6b0cd63
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "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-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded bus v1.4.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4e40eeb0239273c19c0e60402623a559cacbf9f0f7bb0b8c29c5e120519dff53
[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" "4e40eeb0239273c19c0e60402623a559cacbf9f0f7bb0b8c29c5e120519dff53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4e40eeb0239273c19c0e60402623a559cacbf9f0f7bb0b8c29c5e120519dff53", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4e40eeb0239273c19c0e60402623a559cacbf9f0f7bb0b8c29c5e120519dff53", kill_on_drop: false }`
[INFO] [stdout] 4e40eeb0239273c19c0e60402623a559cacbf9f0f7bb0b8c29c5e120519dff53
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+b2f80f6008cdafc35b4472bd46afa16cc6b0cd63" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] be03a04da6f3b5803fc51995b938749378667da31683244dbb1f98ac227f89fb
[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" "be03a04da6f3b5803fc51995b938749378667da31683244dbb1f98ac227f89fb", kill_on_drop: false }`
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]     Checking atomic-option v0.1.2
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking smallvec v0.6.13
[INFO] [stderr]     Checking parking_lot_core v0.2.14
[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 4.39s
[INFO] running `Command { std: "docker" "inspect" "be03a04da6f3b5803fc51995b938749378667da31683244dbb1f98ac227f89fb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "be03a04da6f3b5803fc51995b938749378667da31683244dbb1f98ac227f89fb", kill_on_drop: false }`
[INFO] [stdout] be03a04da6f3b5803fc51995b938749378667da31683244dbb1f98ac227f89fb