[INFO] crate async-option 0.1.1 is already in cache
[INFO] checking async-option-0.1.1 against master#450abe80f193ccefbfcd48214d70520f2d507f0e for pr-73084
[INFO] extracting crate async-option 0.1.1 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate async-option 0.1.1 on toolchain 450abe80f193ccefbfcd48214d70520f2d507f0e
[INFO] running `"/workspace/cargo-home/bin/cargo" "+450abe80f193ccefbfcd48214d70520f2d507f0e" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate async-option 0.1.1
[INFO] finished tweaking crates.io crate async-option 0.1.1
[INFO] tweaked toml for crates.io crate async-option 0.1.1 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+450abe80f193ccefbfcd48214d70520f2d507f0e" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+450abe80f193ccefbfcd48214d70520f2d507f0e" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "/opt/rustwide/cargo-home/bin/cargo" "+450abe80f193ccefbfcd48214d70520f2d507f0e" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] f2dbdd37d0e111b16f913be38b79165a4c32690800cfc8d513a7d9597ae09713
[INFO] running `"docker" "start" "-a" "f2dbdd37d0e111b16f913be38b79165a4c32690800cfc8d513a7d9597ae09713"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]     Checking tokio-mock-task v0.1.1
[INFO] [stderr]     Checking async-option v0.1.1 (/opt/rustwide/workdir)
[INFO] [stderr] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stderr]   --> src/lib.rs:96:17
[INFO] [stderr]    |
[INFO] [stderr] 96 |                 mem::replace(self, CellValue::Fin(None));
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stderr]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] error: unused return value of `std::mem::replace` that must be used
[INFO] [stderr]   --> src/lib.rs:96:17
[INFO] [stderr]    |
[INFO] [stderr] 96 |                 mem::replace(self, CellValue::Fin(None));
[INFO] [stderr]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr] note: the lint level is defined here
[INFO] [stderr]   --> src/lib.rs:26:24
[INFO] [stderr]    |
[INFO] [stderr] 26 | #![cfg_attr(test, deny(warnings))]
[INFO] [stderr]    |                        ^^^^^^^^
[INFO] [stderr]    = note: `#[deny(unused_must_use)]` implied by `#[deny(warnings)]`
[INFO] [stderr]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] error: could not compile `async-option`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "f2dbdd37d0e111b16f913be38b79165a4c32690800cfc8d513a7d9597ae09713"`
[INFO] running `"docker" "rm" "-f" "f2dbdd37d0e111b16f913be38b79165a4c32690800cfc8d513a7d9597ae09713"`
[INFO] [stdout] f2dbdd37d0e111b16f913be38b79165a4c32690800cfc8d513a7d9597ae09713