[INFO] fetching crate discard 1.0.4...
[INFO] checking discard-1.0.4 against master#9503ea19edbf01b9435e80e17d60ce1b88390116 for pr-81782
[INFO] extracting crate discard 1.0.4 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate discard 1.0.4 on toolchain 9503ea19edbf01b9435e80e17d60ce1b88390116
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9503ea19edbf01b9435e80e17d60ce1b88390116" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate discard 1.0.4
[INFO] finished tweaking crates.io crate discard 1.0.4
[INFO] tweaked toml for crates.io crate discard 1.0.4 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9503ea19edbf01b9435e80e17d60ce1b88390116" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9503ea19edbf01b9435e80e17d60ce1b88390116" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+9503ea19edbf01b9435e80e17d60ce1b88390116" "metadata" "--no-deps" "--format-version=1", 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] baf860c2950176bb5b3ab525b5116e7d0cb79bee7932d1cde5c76d1f7cc75c35
[INFO] running `Command { std: "docker" "start" "-a" "baf860c2950176bb5b3ab525b5116e7d0cb79bee7932d1cde5c76d1f7cc75c35", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "baf860c2950176bb5b3ab525b5116e7d0cb79bee7932d1cde5c76d1f7cc75c35", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "baf860c2950176bb5b3ab525b5116e7d0cb79bee7932d1cde5c76d1f7cc75c35", kill_on_drop: false }`
[INFO] [stdout] baf860c2950176bb5b3ab525b5116e7d0cb79bee7932d1cde5c76d1f7cc75c35
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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:f2f6bcd4b43ebee4e173f653a26493129bdb64017c85f916b780ca7fbdbaa79d" "/opt/rustwide/cargo-home/bin/cargo" "+9503ea19edbf01b9435e80e17d60ce1b88390116" "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] 10f3857102459233742bb2179bb9e7fb8ab6ce2f2a6edc19a23ca0ef47c2d86d
[INFO] running `Command { std: "docker" "start" "-a" "10f3857102459233742bb2179bb9e7fb8ab6ce2f2a6edc19a23ca0ef47c2d86d", kill_on_drop: false }`
[INFO] [stderr]     Checking discard v1.0.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `DiscardOnDrop` that must be used
[INFO] [stdout]    --> src/lib.rs:261:9
[INFO] [stdout]     |
[INFO] [stdout] 261 |         DiscardOnDrop::new(Foo::new());
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: 
[INFO] [stdout]             The DiscardOnDrop is unused, which causes it to be immediately discarded.
[INFO] [stdout]             You probably don't want that to happen.
[INFO] [stdout]             
[INFO] [stdout]             How to fix this:
[INFO] [stdout]             
[INFO] [stdout]               * Store the DiscardOnDrop in a variable or data structure.
[INFO] [stdout]             
[INFO] [stdout]               * Or use the DiscardOnDrop::leak function which will cause it to not be
[INFO] [stdout]                 discarded (this *will* leak memory!).
[INFO] [stdout]             
[INFO] [stdout]             See the DiscardOnDrop documentation for more details.
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `DiscardOnDrop` that must be used
[INFO] [stdout]    --> src/lib.rs:262:9
[INFO] [stdout]     |
[INFO] [stdout] 262 |         DiscardOnDrop::new(Foo::new());
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: 
[INFO] [stdout]             The DiscardOnDrop is unused, which causes it to be immediately discarded.
[INFO] [stdout]             You probably don't want that to happen.
[INFO] [stdout]             
[INFO] [stdout]             How to fix this:
[INFO] [stdout]             
[INFO] [stdout]               * Store the DiscardOnDrop in a variable or data structure.
[INFO] [stdout]             
[INFO] [stdout]               * Or use the DiscardOnDrop::leak function which will cause it to not be
[INFO] [stdout]                 discarded (this *will* leak memory!).
[INFO] [stdout]             
[INFO] [stdout]             See the DiscardOnDrop documentation for more details.
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.70s
[INFO] running `Command { std: "docker" "inspect" "10f3857102459233742bb2179bb9e7fb8ab6ce2f2a6edc19a23ca0ef47c2d86d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "10f3857102459233742bb2179bb9e7fb8ab6ce2f2a6edc19a23ca0ef47c2d86d", kill_on_drop: false }`
[INFO] [stdout] 10f3857102459233742bb2179bb9e7fb8ab6ce2f2a6edc19a23ca0ef47c2d86d