[INFO] fetching crate maybe-serde 0.2.1...
[INFO] testing maybe-serde-0.2.1 against master#5d5ff84130da0d74c6ece368dbe821d8f83fa526 for pr-79296
[INFO] extracting crate maybe-serde 0.2.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate maybe-serde 0.2.1 on toolchain 5d5ff84130da0d74c6ece368dbe821d8f83fa526
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "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-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a844560b853492dcfb17073dfb8304cfbb733bd849e292a47847ad14090eaed7
[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" "a844560b853492dcfb17073dfb8304cfbb733bd849e292a47847ad14090eaed7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a844560b853492dcfb17073dfb8304cfbb733bd849e292a47847ad14090eaed7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a844560b853492dcfb17073dfb8304cfbb733bd849e292a47847ad14090eaed7", kill_on_drop: false }`
[INFO] [stdout] a844560b853492dcfb17073dfb8304cfbb733bd849e292a47847ad14090eaed7
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4f1b9da9345308eac1be8086fa797534cd3dbf8c0889727884f5d361a7bcf01c
[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" "4f1b9da9345308eac1be8086fa797534cd3dbf8c0889727884f5d361a7bcf01c", kill_on_drop: false }`
[INFO] [stderr]    Compiling 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]   = 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] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 0.55s
[INFO] running `Command { std: "docker" "inspect" "4f1b9da9345308eac1be8086fa797534cd3dbf8c0889727884f5d361a7bcf01c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f1b9da9345308eac1be8086fa797534cd3dbf8c0889727884f5d361a7bcf01c", kill_on_drop: false }`
[INFO] [stdout] 4f1b9da9345308eac1be8086fa797534cd3dbf8c0889727884f5d361a7bcf01c
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d0933d4af41a0bf8331fba92f27908348e678154e790057136b34f977c30e4af
[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" "d0933d4af41a0bf8331fba92f27908348e678154e790057136b34f977c30e4af", kill_on_drop: false }`
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling syn v1.0.52
[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] [stderr]    Compiling serde_json v1.0.59
[INFO] [stderr]    Compiling serde_derive v1.0.117
[INFO] [stderr]    Compiling 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]   = 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] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 24.51s
[INFO] running `Command { std: "docker" "inspect" "d0933d4af41a0bf8331fba92f27908348e678154e790057136b34f977c30e4af", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d0933d4af41a0bf8331fba92f27908348e678154e790057136b34f977c30e4af", kill_on_drop: false }`
[INFO] [stdout] d0933d4af41a0bf8331fba92f27908348e678154e790057136b34f977c30e4af
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+5d5ff84130da0d74c6ece368dbe821d8f83fa526" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 7648e4cbf06f7acc4effff48c34050266a4dd925764a93b839eadb33c45be9da
[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" "7648e4cbf06f7acc4effff48c34050266a4dd925764a93b839eadb33c45be9da", kill_on_drop: false }`
[INFO] [stderr] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stderr]  --> src/lib.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(specialization)]
[INFO] [stderr]   |            ^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stderr]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stderr]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stderr]  --> src/lib.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(specialization)]
[INFO] [stderr]   |            ^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stderr]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stderr]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.05s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/maybe_serde-8b7f7b204cb15649
[INFO] [stdout] 
[INFO] [stdout] running 4 tests
[INFO] [stdout] test tests::serde_none ... ok
[INFO] [stdout] test tests::serde_none_maybe_serde ... ok
[INFO] [stdout] test tests::serde_some ... ok
[INFO] [stdout] test tests::serde_some_maybe_serde ... ok
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 4 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] [stderr]    Doc-tests maybe-serde
[INFO] [stderr] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stderr]  --> /opt/rustwide/workdir/src/lib.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(specialization)]
[INFO] [stderr]   |            ^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stderr]   = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stderr]   = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stderr] 
[INFO] [stderr] warning: 1 warning emitted
[INFO] [stderr] 
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "7648e4cbf06f7acc4effff48c34050266a4dd925764a93b839eadb33c45be9da", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7648e4cbf06f7acc4effff48c34050266a4dd925764a93b839eadb33c45be9da", kill_on_drop: false }`
[INFO] [stdout] 7648e4cbf06f7acc4effff48c34050266a4dd925764a93b839eadb33c45be9da