[INFO] fetching crate discard 1.0.4...
[INFO] checking discard-1.0.4 against try#05c8870159e4f328578a970e125aa76d24f03b56 for pr-76219
[INFO] extracting crate discard 1.0.4 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate discard 1.0.4 on toolchain 05c8870159e4f328578a970e125aa76d24f03b56
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+05c8870159e4f328578a970e125aa76d24f03b56" "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-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+05c8870159e4f328578a970e125aa76d24f03b56" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+05c8870159e4f328578a970e125aa76d24f03b56" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "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" "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" "+05c8870159e4f328578a970e125aa76d24f03b56" "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] aec68ca580ffacfe9d1b9e87cafc55424617bec471162e43eaa7a159f60c2c69
[INFO] running `Command { std: "docker" "start" "-a" "aec68ca580ffacfe9d1b9e87cafc55424617bec471162e43eaa7a159f60c2c69", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "aec68ca580ffacfe9d1b9e87cafc55424617bec471162e43eaa7a159f60c2c69", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aec68ca580ffacfe9d1b9e87cafc55424617bec471162e43eaa7a159f60c2c69", kill_on_drop: false }`
[INFO] [stdout] aec68ca580ffacfe9d1b9e87cafc55424617bec471162e43eaa7a159f60c2c69
[INFO] running `Command { std: "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" "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" "+05c8870159e4f328578a970e125aa76d24f03b56" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 8bed52a32288ed138ca3cbd14a861c74e217a312febcff5bbb1e2d9b95c8c2bb
[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" "8bed52a32288ed138ca3cbd14a861c74e217a312febcff5bbb1e2d9b95c8c2bb", 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 0.36s
[INFO] running `Command { std: "docker" "inspect" "8bed52a32288ed138ca3cbd14a861c74e217a312febcff5bbb1e2d9b95c8c2bb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8bed52a32288ed138ca3cbd14a861c74e217a312febcff5bbb1e2d9b95c8c2bb", kill_on_drop: false }`
[INFO] [stdout] 8bed52a32288ed138ca3cbd14a861c74e217a312febcff5bbb1e2d9b95c8c2bb