[INFO] fetching crate async-option 0.1.1...
[INFO] checking async-option-0.1.1 against master#f609b7e0586f81fefb3523e3e17adf779ac416be for pr-129466-2
[INFO] extracting crate async-option 0.1.1 into /workspace/builds/worker-7-tc1/source
[INFO] validating manifest of crates.io crate async-option 0.1.1 on toolchain f609b7e0586f81fefb3523e3e17adf779ac416be
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[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-7-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 57 packages to latest compatible versions
[INFO] [stderr]       Adding bitflags v1.3.2 (available: v2.6.0)
[INFO] [stderr]       Adding bytes v0.4.12 (available: v1.7.2)
[INFO] [stderr]       Adding cfg-if v0.1.10 (available: v1.0.0)
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[INFO] [stderr]       Adding crossbeam-queue v0.2.3 (available: v0.3.11)
[INFO] [stderr]       Adding crossbeam-utils v0.7.2 (available: v0.8.20)
[INFO] [stderr]       Adding futures v0.1.31 (available: v0.3.30)
[INFO] [stderr]       Adding hermit-abi v0.3.9 (available: v0.4.0)
[INFO] [stderr]       Adding lock_api v0.3.4 (available: v0.4.12)
[INFO] [stderr]       Adding memoffset v0.5.6 (available: v0.9.1)
[INFO] [stderr]       Adding mio v0.6.23 (available: v1.0.2)
[INFO] [stderr]       Adding miow v0.2.2 (available: v0.6.0)
[INFO] [stderr]       Adding parking_lot v0.9.0 (available: v0.12.3)
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[INFO] [stderr]       Adding redox_syscall v0.1.57 (available: v0.5.6)
[INFO] [stderr]       Adding rustc_version v0.2.3 (available: v0.4.1)
[INFO] [stderr]       Adding semver v0.9.0 (available: v1.0.23)
[INFO] [stderr]       Adding semver-parser v0.7.0 (available: v0.10.2)
[INFO] [stderr]       Adding smallvec v0.6.14 (available: v1.13.2)
[INFO] [stderr]       Adding tokio v0.1.22 (available: v1.40.0)
[INFO] [stderr]       Adding winapi v0.2.8 (available: v0.3.9)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded tokio-mock-task v0.1.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 946f685c81ac685fe8253eb15a9ef726d3796e438ac267e1c876c28a74bebec5
[INFO] running `Command { std: "docker" "start" "-a" "946f685c81ac685fe8253eb15a9ef726d3796e438ac267e1c876c28a74bebec5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "946f685c81ac685fe8253eb15a9ef726d3796e438ac267e1c876c28a74bebec5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "946f685c81ac685fe8253eb15a9ef726d3796e438ac267e1c876c28a74bebec5", kill_on_drop: false }`
[INFO] [stdout] 946f685c81ac685fe8253eb15a9ef726d3796e438ac267e1c876c28a74bebec5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/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" "RUSTDOCFLAGS=--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:ceb6ea022f8a89cebbe621bb4987e73a935bd40dfbb726f832cfff4742a5b95a" "/opt/rustwide/cargo-home/bin/cargo" "+f609b7e0586f81fefb3523e3e17adf779ac416be" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] de8d44bbc317199a481215956703051442620e93445aef8651914a5a5acb0761
[INFO] running `Command { std: "docker" "start" "-a" "de8d44bbc317199a481215956703051442620e93445aef8651914a5a5acb0761", kill_on_drop: false }`
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]     Checking futures v0.1.31
[INFO] [stderr]     Checking lazy_static v1.5.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
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[INFO] [stderr]     Checking byteorder v1.5.0
[INFO] [stderr]    Compiling memoffset v0.5.6
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]     Checking lock_api v0.3.4
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking num_cpus v1.16.0
[INFO] [stderr]     Checking net2 v0.2.39
[INFO] [stderr]     Checking smallvec v0.6.14
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]     Checking mio v0.6.23
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling parking_lot_core v0.6.3
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]     Checking crossbeam-queue v0.2.3
[INFO] [stderr]     Checking mio-uds v0.6.8
[INFO] [stderr]     Checking crossbeam-deque v0.7.4
[INFO] [stderr]     Checking tokio-executor v0.1.10
[INFO] [stderr]     Checking tokio-io v0.1.13
[INFO] [stderr]     Checking tokio-sync v0.1.8
[INFO] [stderr]     Checking tokio-mock-task v0.1.1
[INFO] [stderr]     Checking tokio-threadpool v0.1.18
[INFO] [stderr]     Checking tokio-current-thread v0.1.7
[INFO] [stderr]     Checking tokio-timer v0.2.13
[INFO] [stderr]     Checking async-option v0.1.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking tokio-reactor v0.1.12
[INFO] [stderr]     Checking tokio-codec v0.1.2
[INFO] [stdout] warning: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/lib.rs:96:17
[INFO] [stdout]    |
[INFO] [stdout] 96 |                 mem::replace(self, CellValue::Fin(None));
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout]    = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 96 |                 let _ = mem::replace(self, CellValue::Fin(None));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking tokio-tcp v0.1.4
[INFO] [stderr]     Checking tokio-uds v0.2.7
[INFO] [stderr]     Checking tokio-udp v0.1.6
[INFO] [stderr]     Checking tokio-fs v0.1.7
[INFO] [stderr]     Checking tokio v0.1.22
[INFO] [stdout] error: unused return value of `std::mem::replace` that must be used
[INFO] [stdout]   --> src/lib.rs:96:17
[INFO] [stdout]    |
[INFO] [stdout] 96 |                 mem::replace(self, CellValue::Fin(None));
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: if you don't need the old value, you can just assign the new value directly
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]   --> src/lib.rs:26:24
[INFO] [stdout]    |
[INFO] [stdout] 26 | #![cfg_attr(test, deny(warnings))]
[INFO] [stdout]    |                        ^^^^^^^^
[INFO] [stdout]    = note: `#[deny(unused_must_use)]` implied by `#[deny(warnings)]`
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]    |
[INFO] [stdout] 96 |                 let _ = mem::replace(self, CellValue::Fin(None));
[INFO] [stdout]    |                 +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 1 previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `async-option` (lib test) due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "de8d44bbc317199a481215956703051442620e93445aef8651914a5a5acb0761", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "de8d44bbc317199a481215956703051442620e93445aef8651914a5a5acb0761", kill_on_drop: false }`
[INFO] [stdout] de8d44bbc317199a481215956703051442620e93445aef8651914a5a5acb0761