[INFO] fetching crate metamorphose 0.4.4...
[INFO] checking metamorphose-0.4.4 against try#8de4b308b608cded0ebccf658a0fc719bce87d4e for pr-89056
[INFO] extracting crate metamorphose 0.4.4 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate metamorphose 0.4.4 on toolchain 8de4b308b608cded0ebccf658a0fc719bce87d4e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate metamorphose 0.4.4
[INFO] finished tweaking crates.io crate metamorphose 0.4.4
[INFO] tweaked toml for crates.io crate metamorphose 0.4.4 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "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" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 47d9015118285ef37e1dfb92e9893bf1051ae5d2d819c39f10bf03848f929f2b
[INFO] running `Command { std: "docker" "start" "-a" "47d9015118285ef37e1dfb92e9893bf1051ae5d2d819c39f10bf03848f929f2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "47d9015118285ef37e1dfb92e9893bf1051ae5d2d819c39f10bf03848f929f2b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "47d9015118285ef37e1dfb92e9893bf1051ae5d2d819c39f10bf03848f929f2b", kill_on_drop: false }`
[INFO] [stdout] 47d9015118285ef37e1dfb92e9893bf1051ae5d2d819c39f10bf03848f929f2b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+8de4b308b608cded0ebccf658a0fc719bce87d4e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] cbf2c899c8b5543e372ffebe2574472f93cc060fda74e67f1655c0f1d6b47306
[INFO] running `Command { std: "docker" "start" "-a" "cbf2c899c8b5543e372ffebe2574472f93cc060fda74e67f1655c0f1d6b47306", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.29
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling serde_derive v1.0.130
[INFO] [stderr]    Compiling serde v1.0.130
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling serde_json v1.0.68
[INFO] [stderr]     Checking itoa v0.4.8
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]    Compiling aho-corasick v0.7.18
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]     Checking metamorphose v0.4.4 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused borrow that must be used
[INFO] [stdout]    --> src/lib.rs:293:13
[INFO] [stdout]     |
[INFO] [stdout] 293 |             &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] 293 |             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:293:13
[INFO] [stdout]     |
[INFO] [stdout] 293 |             &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] 293 |             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:293:13
[INFO] [stdout]     |
[INFO] [stdout] 293 |             &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] 293 |             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 34.36s
[INFO] running `Command { std: "docker" "inspect" "cbf2c899c8b5543e372ffebe2574472f93cc060fda74e67f1655c0f1d6b47306", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "cbf2c899c8b5543e372ffebe2574472f93cc060fda74e67f1655c0f1d6b47306", kill_on_drop: false }`
[INFO] [stdout] cbf2c899c8b5543e372ffebe2574472f93cc060fda74e67f1655c0f1d6b47306