[INFO] fetching crate discard 1.0.4...
[INFO] checking discard-1.0.4 against master#430feb24a46993e5073c1bb1b39da190d83fa2bf for pr-78363
[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 430feb24a46993e5073c1bb1b39da190d83fa2bf
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+430feb24a46993e5073c1bb1b39da190d83fa2bf" "read-manifest" "--manifest-path" "Cargo.toml", 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" "+430feb24a46993e5073c1bb1b39da190d83fa2bf" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+430feb24a46993e5073c1bb1b39da190d83fa2bf" "fetch" "--locked" "--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-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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+430feb24a46993e5073c1bb1b39da190d83fa2bf" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0fc4c8fd350c184ebfb5c078856c9784ecc115b6e6d34b3e3090dbb40b320a09
[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" "0fc4c8fd350c184ebfb5c078856c9784ecc115b6e6d34b3e3090dbb40b320a09", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0fc4c8fd350c184ebfb5c078856c9784ecc115b6e6d34b3e3090dbb40b320a09", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0fc4c8fd350c184ebfb5c078856c9784ecc115b6e6d34b3e3090dbb40b320a09", kill_on_drop: false }`
[INFO] [stdout] 0fc4c8fd350c184ebfb5c078856c9784ecc115b6e6d34b3e3090dbb40b320a09
[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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+430feb24a46993e5073c1bb1b39da190d83fa2bf" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 277f07757c9010d8ff08427c80a9d27ca47b2cba7ea962a5cfdd5246de1523d4
[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" "277f07757c9010d8ff08427c80a9d27ca47b2cba7ea962a5cfdd5246de1523d4", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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 0.56s
[INFO] running `Command { std: "docker" "inspect" "277f07757c9010d8ff08427c80a9d27ca47b2cba7ea962a5cfdd5246de1523d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "277f07757c9010d8ff08427c80a9d27ca47b2cba7ea962a5cfdd5246de1523d4", kill_on_drop: false }`
[INFO] [stdout] 277f07757c9010d8ff08427c80a9d27ca47b2cba7ea962a5cfdd5246de1523d4