[INFO] fetching crate nop-json 1.0.1...
[INFO] checking nop-json-1.0.1 against master#c919f490bbcd2b29b74016101f7ec71aaa24bdbb for pr-79073
[INFO] extracting crate nop-json 1.0.1 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate nop-json 1.0.1 on toolchain c919f490bbcd2b29b74016101f7ec71aaa24bdbb
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c919f490bbcd2b29b74016101f7ec71aaa24bdbb" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate nop-json 1.0.1
[INFO] finished tweaking crates.io crate nop-json 1.0.1
[INFO] tweaked toml for crates.io crate nop-json 1.0.1 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c919f490bbcd2b29b74016101f7ec71aaa24bdbb" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+c919f490bbcd2b29b74016101f7ec71aaa24bdbb" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+c919f490bbcd2b29b74016101f7ec71aaa24bdbb" "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] faa6d1ebb8a90f9d3d86883e743a1f226f4af89175378cf9e51513005ebecc0c
[INFO] running `Command { std: "docker" "start" "-a" "faa6d1ebb8a90f9d3d86883e743a1f226f4af89175378cf9e51513005ebecc0c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "faa6d1ebb8a90f9d3d86883e743a1f226f4af89175378cf9e51513005ebecc0c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "faa6d1ebb8a90f9d3d86883e743a1f226f4af89175378cf9e51513005ebecc0c", kill_on_drop: false }`
[INFO] [stdout] faa6d1ebb8a90f9d3d86883e743a1f226f4af89175378cf9e51513005ebecc0c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+c919f490bbcd2b29b74016101f7ec71aaa24bdbb" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 06b99aa73266c639d863be8f880754bdb02222a587ed88e8eac52b5dfa7c7519
[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" "06b99aa73266c639d863be8f880754bdb02222a587ed88e8eac52b5dfa7c7519", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.50
[INFO] [stderr]     Checking numtoa v0.2.3
[INFO] [stderr]    Compiling nop-json-derive v1.1.1
[INFO] [stderr]     Checking nop-json v1.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]   = help: consider using `min_specialization` instead, which is more stable and complete
[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 12.92s
[INFO] running `Command { std: "docker" "inspect" "06b99aa73266c639d863be8f880754bdb02222a587ed88e8eac52b5dfa7c7519", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "06b99aa73266c639d863be8f880754bdb02222a587ed88e8eac52b5dfa7c7519", kill_on_drop: false }`
[INFO] [stdout] 06b99aa73266c639d863be8f880754bdb02222a587ed88e8eac52b5dfa7c7519