[INFO] fetching crate slot 0.2.5...
[INFO] checking slot-0.2.5 against try#6024cfef3a82f9a7688f07054f1650081bad3af5 for pr-74130
[INFO] extracting crate slot 0.2.5 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate slot 0.2.5 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 crates.io crate slot 0.2.5
[INFO] finished tweaking crates.io crate slot 0.2.5
[INFO] tweaked toml for crates.io crate slot 0.2.5 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+6024cfef3a82f9a7688f07054f1650081bad3af5" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] 4a2241faf073947fdb893adfbde5541b0ac9059ab9fd4e561f07427bfcd0658b
[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" "4a2241faf073947fdb893adfbde5541b0ac9059ab9fd4e561f07427bfcd0658b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4a2241faf073947fdb893adfbde5541b0ac9059ab9fd4e561f07427bfcd0658b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4a2241faf073947fdb893adfbde5541b0ac9059ab9fd4e561f07427bfcd0658b", kill_on_drop: false }`
[INFO] [stdout] 4a2241faf073947fdb893adfbde5541b0ac9059ab9fd4e561f07427bfcd0658b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 275380d0091f687244d801113b339a178a9c0cea21bfa2045c6b4bdefbe06005
[INFO] running `Command { std: "docker" "start" "-a" "275380d0091f687244d801113b339a178a9c0cea21bfa2045c6b4bdefbe06005", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking slot v0.2.5 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]  --> src/lib.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 | #[allow(unions_with_drop_fields)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unknown_lints)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]   --> src/lib.rs:16:17
[INFO] [stdout]    |
[INFO] [stdout] 16 |         #[allow(unions_with_drop_fields)]
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]  --> src/lib.rs:9:9
[INFO] [stdout]   |
[INFO] [stdout] 9 | #[allow(unions_with_drop_fields)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unknown_lints)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unknown lint: `unions_with_drop_fields`
[INFO] [stdout]   --> src/lib.rs:16:17
[INFO] [stdout]    |
[INFO] [stdout] 16 |         #[allow(unions_with_drop_fields)]
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0740]: unions may not contain fields that need dropping
[INFO] [stdout]   --> src/lib.rs:11:21
[INFO] [stdout]    |
[INFO] [stdout] 11 | pub union Slot<T> { pub x: T }
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: `std::mem::ManuallyDrop` can be used to wrap the type
[INFO] [stdout]   --> src/lib.rs:11:21
[INFO] [stdout]    |
[INFO] [stdout] 11 | pub union Slot<T> { pub x: T }
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0740`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `slot`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error[E0740]: unions may not contain fields that need dropping
[INFO] [stdout]   --> src/lib.rs:11:21
[INFO] [stdout]    |
[INFO] [stdout] 11 | pub union Slot<T> { pub x: T }
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout] note: `std::mem::ManuallyDrop` can be used to wrap the type
[INFO] [stdout]   --> src/lib.rs:11:21
[INFO] [stdout]    |
[INFO] [stdout] 11 | pub union Slot<T> { pub x: T }
[INFO] [stdout]    |                     ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0740`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "275380d0091f687244d801113b339a178a9c0cea21bfa2045c6b4bdefbe06005", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "275380d0091f687244d801113b339a178a9c0cea21bfa2045c6b4bdefbe06005", kill_on_drop: false }`
[INFO] [stdout] 275380d0091f687244d801113b339a178a9c0cea21bfa2045c6b4bdefbe06005