[INFO] crate maybe-serde 0.2.1 is already in cache
[INFO] checking maybe-serde-0.2.1 against try#5fdfba63a96c5e8ae0ebf6b8b66853110277087d for pr-73166
[INFO] extracting crate maybe-serde 0.2.1 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate maybe-serde 0.2.1 on toolchain 5fdfba63a96c5e8ae0ebf6b8b66853110277087d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5fdfba63a96c5e8ae0ebf6b8b66853110277087d" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate maybe-serde 0.2.1
[INFO] finished tweaking crates.io crate maybe-serde 0.2.1
[INFO] tweaked toml for crates.io crate maybe-serde 0.2.1 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5fdfba63a96c5e8ae0ebf6b8b66853110277087d" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5fdfba63a96c5e8ae0ebf6b8b66853110277087d" "fetch" "--locked" "--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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+5fdfba63a96c5e8ae0ebf6b8b66853110277087d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 9797b5da1ec73823547398f94ed06d309148fb3e0c0b72f9a24876f942cf9c2d
[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" "9797b5da1ec73823547398f94ed06d309148fb3e0c0b72f9a24876f942cf9c2d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "9797b5da1ec73823547398f94ed06d309148fb3e0c0b72f9a24876f942cf9c2d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9797b5da1ec73823547398f94ed06d309148fb3e0c0b72f9a24876f942cf9c2d", kill_on_drop: false }`
[INFO] [stdout] 9797b5da1ec73823547398f94ed06d309148fb3e0c0b72f9a24876f942cf9c2d
[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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:38e1b949b06cde1964af550a6e548bd9b2b2ea170003ae122f8fc0886596cc07" "/opt/rustwide/cargo-home/bin/cargo" "+5fdfba63a96c5e8ae0ebf6b8b66853110277087d" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f7a5f920f598c7a834d639fed942bb1d3304191831423f562f837f1f2feccdbd
[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" "f7a5f920f598c7a834d639fed942bb1d3304191831423f562f837f1f2feccdbd", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.19
[INFO] [stderr]    Compiling serde v1.0.114
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.35
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling serde_json v1.0.56
[INFO] [stderr]    Compiling serde_derive v1.0.114
[INFO] [stderr]     Checking itoa v0.4.6
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]     Checking maybe-serde v0.2.1 (/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] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[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] 
[INFO] [stdout] 
[INFO] [stdout] warning: 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 17.36s
[INFO] running `Command { std: "docker" "inspect" "f7a5f920f598c7a834d639fed942bb1d3304191831423f562f837f1f2feccdbd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f7a5f920f598c7a834d639fed942bb1d3304191831423f562f837f1f2feccdbd", kill_on_drop: false }`
[INFO] [stdout] f7a5f920f598c7a834d639fed942bb1d3304191831423f562f837f1f2feccdbd