[INFO] fetching crate slot 0.2.5...
[INFO] checking slot-0.2.5 against try#b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f for pr-76104
[INFO] extracting crate slot 0.2.5 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate slot 0.2.5 on toolchain b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "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-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 979f6e5c7f0677b860692af2d04e2ddc1a0d03906eb1d05aa90028e74a1d59ed
[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" "979f6e5c7f0677b860692af2d04e2ddc1a0d03906eb1d05aa90028e74a1d59ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "979f6e5c7f0677b860692af2d04e2ddc1a0d03906eb1d05aa90028e74a1d59ed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "979f6e5c7f0677b860692af2d04e2ddc1a0d03906eb1d05aa90028e74a1d59ed", kill_on_drop: false }`
[INFO] [stdout] 979f6e5c7f0677b860692af2d04e2ddc1a0d03906eb1d05aa90028e74a1d59ed
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+b1cc2963e8346ba1f5afb1edb86dbcf3f9ef0c5f" "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] a9becbd393ec830398148d83a9db58f0210329f3b6a7cca73bd82ccc805f61be
[INFO] running `Command { std: "docker" "start" "-a" "a9becbd393ec830398148d83a9db58f0210329f3b6a7cca73bd82ccc805f61be", kill_on_drop: false }`
[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[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] [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] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "a9becbd393ec830398148d83a9db58f0210329f3b6a7cca73bd82ccc805f61be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a9becbd393ec830398148d83a9db58f0210329f3b6a7cca73bd82ccc805f61be", kill_on_drop: false }`
[INFO] [stdout] a9becbd393ec830398148d83a9db58f0210329f3b6a7cca73bd82ccc805f61be