[INFO] fetching crate maybe-serde 0.2.1...
[INFO] checking maybe-serde-0.2.1 against try#ffa4a0215752773248fb0f0a8092f1c3e7907e9e for pr-75585
[INFO] extracting crate maybe-serde 0.2.1 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate maybe-serde 0.2.1 on toolchain ffa4a0215752773248fb0f0a8092f1c3e7907e9e
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "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-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1a5a8bf2c22546b85d13247ea1eddff178b4da72a16f5d6fe32e42f64613a90f
[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" "1a5a8bf2c22546b85d13247ea1eddff178b4da72a16f5d6fe32e42f64613a90f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1a5a8bf2c22546b85d13247ea1eddff178b4da72a16f5d6fe32e42f64613a90f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1a5a8bf2c22546b85d13247ea1eddff178b4da72a16f5d6fe32e42f64613a90f", kill_on_drop: false }`
[INFO] [stdout] 1a5a8bf2c22546b85d13247ea1eddff178b4da72a16f5d6fe32e42f64613a90f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+ffa4a0215752773248fb0f0a8092f1c3e7907e9e" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 66efed74a9aa1622054e544c162f1ea157bea3372691679d605767d208ca30dd
[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" "66efed74a9aa1622054e544c162f1ea157bea3372691679d605767d208ca30dd", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.20
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling serde v1.0.115
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling serde_json v1.0.57
[INFO] [stderr]    Compiling serde_derive v1.0.115
[INFO] [stderr]     Checking itoa v0.4.6
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling syn v1.0.39
[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 25.08s
[INFO] running `Command { std: "docker" "inspect" "66efed74a9aa1622054e544c162f1ea157bea3372691679d605767d208ca30dd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "66efed74a9aa1622054e544c162f1ea157bea3372691679d605767d208ca30dd", kill_on_drop: false }`
[INFO] [stdout] 66efed74a9aa1622054e544c162f1ea157bea3372691679d605767d208ca30dd