[INFO] fetching crate metamorphose 0.3.2...
[INFO] checking metamorphose-0.3.2 against master#8007b506ac5da629f223b755f5a5391edd5f6d01 for pr-88041
[INFO] extracting crate metamorphose 0.3.2 into /workspace/builds/worker-33/source
[INFO] validating manifest of crates.io crate metamorphose 0.3.2 on toolchain 8007b506ac5da629f223b755f5a5391edd5f6d01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate metamorphose 0.3.2
[INFO] finished tweaking crates.io crate metamorphose 0.3.2
[INFO] tweaked toml for crates.io crate metamorphose 0.3.2 written to /workspace/builds/worker-33/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "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" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/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" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] f1ff79d7b352befe01e9f66f82c3b4a4f13b2ddc64a861c1752ab28864b0c2db
[INFO] running `Command { std: "docker" "start" "-a" "f1ff79d7b352befe01e9f66f82c3b4a4f13b2ddc64a861c1752ab28864b0c2db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f1ff79d7b352befe01e9f66f82c3b4a4f13b2ddc64a861c1752ab28864b0c2db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f1ff79d7b352befe01e9f66f82c3b4a4f13b2ddc64a861c1752ab28864b0c2db", kill_on_drop: false }`
[INFO] [stdout] f1ff79d7b352befe01e9f66f82c3b4a4f13b2ddc64a861c1752ab28864b0c2db
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-33/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" "+8007b506ac5da629f223b755f5a5391edd5f6d01" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f1869743fb807bf04fe26e61be27c81649c6a9c6d74ccda01b22d05a64092504
[INFO] running `Command { std: "docker" "start" "-a" "f1869743fb807bf04fe26e61be27c81649c6a9c6d74ccda01b22d05a64092504", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]    Compiling regex-syntax v0.6.25
[INFO] [stderr]     Checking proc-macro2 v1.0.28
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling aho-corasick v0.7.18
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]     Checking quote v1.0.9
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]    Compiling serde_derive v1.0.127
[INFO] [stderr]     Checking serde v1.0.127
[INFO] [stderr]     Checking serde_json v1.0.66
[INFO] [stderr]     Checking metamorphose v0.3.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:296:13
[INFO] [stdout]     |
[INFO] [stdout] 296 |             &fields.push(new_field);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 296 |             let _ = &fields.push(new_field);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:296:13
[INFO] [stdout]     |
[INFO] [stdout] 296 |             &fields.push(new_field);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 296 |             let _ = &fields.push(new_field);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[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:296:13
[INFO] [stdout]     |
[INFO] [stdout] 296 |             &fields.push(new_field);
[INFO] [stdout]     |             ^^^^^^^^^^^^^^^^^^^^^^^ the borrow produces a value
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout] help: use `let _ = ...` to ignore the resulting value
[INFO] [stdout]     |
[INFO] [stdout] 296 |             let _ = &fields.push(new_field);
[INFO] [stdout]     |             +++++++
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 25.27s
[INFO] running `Command { std: "docker" "inspect" "f1869743fb807bf04fe26e61be27c81649c6a9c6d74ccda01b22d05a64092504", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f1869743fb807bf04fe26e61be27c81649c6a9c6d74ccda01b22d05a64092504", kill_on_drop: false }`
[INFO] [stdout] f1869743fb807bf04fe26e61be27c81649c6a9c6d74ccda01b22d05a64092504