[INFO] fetching crate serde_tuple 0.5.0...
[INFO] checking serde_tuple-0.5.0 against master#5e3f1b148db5bfa27fee52464ae1f5d34c49d77b for pr-75502
[INFO] extracting crate serde_tuple 0.5.0 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate serde_tuple 0.5.0 on toolchain 5e3f1b148db5bfa27fee52464ae1f5d34c49d77b
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate serde_tuple 0.5.0
[INFO] finished tweaking crates.io crate serde_tuple 0.5.0
[INFO] tweaked toml for crates.io crate serde_tuple 0.5.0 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate crates.io crate serde_tuple 0.5.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:e18d859f9e32a1da89bc7b2d7d51e13b57342044d1295d9fc0dd0068c58eb3d1" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "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] adf43f764799d854c79b71ea8e23c43248ab4915cd06763c6d093d7ea1e3351f
[INFO] running `Command { std: "docker" "start" "-a" "adf43f764799d854c79b71ea8e23c43248ab4915cd06763c6d093d7ea1e3351f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "adf43f764799d854c79b71ea8e23c43248ab4915cd06763c6d093d7ea1e3351f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "adf43f764799d854c79b71ea8e23c43248ab4915cd06763c6d093d7ea1e3351f", kill_on_drop: false }`
[INFO] [stdout] adf43f764799d854c79b71ea8e23c43248ab4915cd06763c6d093d7ea1e3351f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:e18d859f9e32a1da89bc7b2d7d51e13b57342044d1295d9fc0dd0068c58eb3d1" "/opt/rustwide/cargo-home/bin/cargo" "+5e3f1b148db5bfa27fee52464ae1f5d34c49d77b" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 1292e921dc5360ae82b34866ccc4cbd804ae881e044bedf091c15682d157f541
[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" "1292e921dc5360ae82b34866ccc4cbd804ae881e044bedf091c15682d157f541", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling syn v0.15.36
[INFO] [stderr]    Compiling syn v1.0.13
[INFO] [stderr]    Compiling serde v1.0.92
[INFO] [stderr]    Compiling ryu v0.2.8
[INFO] [stderr]    Compiling proc-macro2 v1.0.7
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling quote v0.6.12
[INFO] [stderr]    Compiling serde_derive v1.0.92
[INFO] [stderr]    Compiling serde_tuple_macros v0.5.0
[INFO] [stderr]     Checking serde_json v1.0.39
[INFO] [stderr]     Checking serde_tuple v0.5.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::borrow::Cow`
[INFO] [stdout]  --> examples/simple.rs:3:5
[INFO] [stdout]   |
[INFO] [stdout] 3 | use std::borrow::Cow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: struct is never constructed: `Ok`
[INFO] [stdout]   --> examples/simple.rs:23:8
[INFO] [stdout]    |
[INFO] [stdout] 23 | struct Ok;
[INFO] [stdout]    |        ^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 2 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 48.49s
[INFO] running `Command { std: "docker" "inspect" "1292e921dc5360ae82b34866ccc4cbd804ae881e044bedf091c15682d157f541", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1292e921dc5360ae82b34866ccc4cbd804ae881e044bedf091c15682d157f541", kill_on_drop: false }`
[INFO] [stdout] 1292e921dc5360ae82b34866ccc4cbd804ae881e044bedf091c15682d157f541