[INFO] fetching crate metamorphose 0.2.59...
[INFO] checking metamorphose-0.2.59 against master#90442458ac46b1d5eed752c316da25450f67285b for pr-81477
[INFO] extracting crate metamorphose 0.2.59 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate metamorphose 0.2.59 on toolchain 90442458ac46b1d5eed752c316da25450f67285b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate metamorphose 0.2.59
[INFO] finished tweaking crates.io crate metamorphose 0.2.59
[INFO] tweaked toml for crates.io crate metamorphose 0.2.59 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "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] c04d2c0e6824b9080b4f4a9d467567ac7b950aa4791f66621c09df029fcfe2b8
[INFO] running `Command { std: "docker" "start" "-a" "c04d2c0e6824b9080b4f4a9d467567ac7b950aa4791f66621c09df029fcfe2b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "c04d2c0e6824b9080b4f4a9d467567ac7b950aa4791f66621c09df029fcfe2b8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c04d2c0e6824b9080b4f4a9d467567ac7b950aa4791f66621c09df029fcfe2b8", kill_on_drop: false }`
[INFO] [stdout] c04d2c0e6824b9080b4f4a9d467567ac7b950aa4791f66621c09df029fcfe2b8
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+90442458ac46b1d5eed752c316da25450f67285b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 04f373f3805a0a18617dbbcd20807195b51e188a5e96a2f92211745176ca1ecf
[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" "04f373f3805a0a18617dbbcd20807195b51e188a5e96a2f92211745176ca1ecf", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.73
[INFO] [stderr]    Compiling serde_json v1.0.64
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling serde_derive v1.0.126
[INFO] [stderr]     Checking serde v1.0.126
[INFO] [stderr]     Checking metamorphose v0.2.59 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:297:13
[INFO] [stdout]     |
[INFO] [stdout] 297 |             &fields.push(new_field);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:297:13
[INFO] [stdout]     |
[INFO] [stdout] 297 |             &fields.push(new_field);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:297:13
[INFO] [stdout]     |
[INFO] [stdout] 297 |             &fields.push(new_field);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 38.47s
[INFO] running `Command { std: "docker" "inspect" "04f373f3805a0a18617dbbcd20807195b51e188a5e96a2f92211745176ca1ecf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "04f373f3805a0a18617dbbcd20807195b51e188a5e96a2f92211745176ca1ecf", kill_on_drop: false }`
[INFO] [stdout] 04f373f3805a0a18617dbbcd20807195b51e188a5e96a2f92211745176ca1ecf