[INFO] fetching crate discard 1.0.4...
[INFO] checking discard-1.0.4 against master#dfd7b8d03fb93d0e03147d28b3be6d93260fa94d for pr-87050
[INFO] extracting crate discard 1.0.4 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate discard 1.0.4 on toolchain dfd7b8d03fb93d0e03147d28b3be6d93260fa94d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "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-11/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 98110817f1c35bf0d42ef14e820a340512cb871a5065fa7015a44a2a8f214fd5
[INFO] running `Command { std: "docker" "start" "-a" "98110817f1c35bf0d42ef14e820a340512cb871a5065fa7015a44a2a8f214fd5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "98110817f1c35bf0d42ef14e820a340512cb871a5065fa7015a44a2a8f214fd5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "98110817f1c35bf0d42ef14e820a340512cb871a5065fa7015a44a2a8f214fd5", kill_on_drop: false }`
[INFO] [stdout] 98110817f1c35bf0d42ef14e820a340512cb871a5065fa7015a44a2a8f214fd5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+dfd7b8d03fb93d0e03147d28b3be6d93260fa94d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 52655a35fdc142ce0710f281fbf3d128fc74482ba2fae2bf39feb1e92f3ee07e
[INFO] running `Command { std: "docker" "start" "-a" "52655a35fdc142ce0710f281fbf3d128fc74482ba2fae2bf39feb1e92f3ee07e", 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 0.26s
[INFO] running `Command { std: "docker" "inspect" "52655a35fdc142ce0710f281fbf3d128fc74482ba2fae2bf39feb1e92f3ee07e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "52655a35fdc142ce0710f281fbf3d128fc74482ba2fae2bf39feb1e92f3ee07e", kill_on_drop: false }`
[INFO] [stdout] 52655a35fdc142ce0710f281fbf3d128fc74482ba2fae2bf39feb1e92f3ee07e