[INFO] fetching crate json_derive 0.0.1-alpha1...
[INFO] checking json_derive-0.0.1-alpha1 against master#8007b506ac5da629f223b755f5a5391edd5f6d01 for pr-88041
[INFO] extracting crate json_derive 0.0.1-alpha1 into /workspace/builds/worker-51/source
[INFO] validating manifest of crates.io crate json_derive 0.0.1-alpha1 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 json_derive 0.0.1-alpha1
[INFO] finished tweaking crates.io crate json_derive 0.0.1-alpha1
[INFO] tweaked toml for crates.io crate json_derive 0.0.1-alpha1 written to /workspace/builds/worker-51/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] 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-51/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-51/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] 60080aa1ead65b2e347920c902bca810ee8608eeb11ce27f26ec2a11fe0f97ad
[INFO] running `Command { std: "docker" "start" "-a" "60080aa1ead65b2e347920c902bca810ee8608eeb11ce27f26ec2a11fe0f97ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "60080aa1ead65b2e347920c902bca810ee8608eeb11ce27f26ec2a11fe0f97ad", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "60080aa1ead65b2e347920c902bca810ee8608eeb11ce27f26ec2a11fe0f97ad", kill_on_drop: false }`
[INFO] [stdout] 60080aa1ead65b2e347920c902bca810ee8608eeb11ce27f26ec2a11fe0f97ad
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-51/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-51/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] 520c53ac94237a65092048eb02f6170546f73578535948ece05174f87bfeb62b
[INFO] running `Command { std: "docker" "start" "-a" "520c53ac94237a65092048eb02f6170546f73578535948ece05174f87bfeb62b", 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] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling ryu v0.2.8
[INFO] [stderr]    Compiling serde v1.0.89
[INFO] [stderr]     Checking unicode-xid v0.1.0
[INFO] [stderr]    Compiling syn v0.15.31
[INFO] [stderr]     Checking hashbrown v0.11.2
[INFO] [stderr]    Compiling indexmap v1.7.0
[INFO] [stderr]     Checking quote v0.6.11
[INFO] [stderr]     Checking serde_json v1.0.39
[INFO] [stderr]     Checking json_derive v0.0.1-alpha1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused extern crate
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | extern crate proc_macro;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
[INFO] [stdout]   |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]  --> src/lib.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![warn(unused_extern_crates)]
[INFO] [stdout]   |         ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused extern crate
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | extern crate proc_macro;
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove it
[INFO] [stdout]   |
[INFO] [stdout] note: the lint level is defined here
[INFO] [stdout]  --> src/lib.rs:3:9
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![warn(unused_extern_crates)]
[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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 8.28s
[INFO] running `Command { std: "docker" "inspect" "520c53ac94237a65092048eb02f6170546f73578535948ece05174f87bfeb62b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "520c53ac94237a65092048eb02f6170546f73578535948ece05174f87bfeb62b", kill_on_drop: false }`
[INFO] [stdout] 520c53ac94237a65092048eb02f6170546f73578535948ece05174f87bfeb62b