[INFO] fetching crate fuzzcheck_mutators 0.5.0...
[INFO] checking fuzzcheck_mutators-0.5.0 against try#9c1dcf141bc0875407c4eb36972857bd3db713e2 for pr-81863
[INFO] extracting crate fuzzcheck_mutators 0.5.0 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate fuzzcheck_mutators 0.5.0 on toolchain 9c1dcf141bc0875407c4eb36972857bd3db713e2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9c1dcf141bc0875407c4eb36972857bd3db713e2" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate fuzzcheck_mutators 0.5.0
[INFO] finished tweaking crates.io crate fuzzcheck_mutators 0.5.0
[INFO] tweaked toml for crates.io crate fuzzcheck_mutators 0.5.0 written to /workspace/builds/worker-3/source/Cargo.toml
[INFO] crate crates.io crate fuzzcheck_mutators 0.5.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+9c1dcf141bc0875407c4eb36972857bd3db713e2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded fuzzcheck_mutators_derive v0.5.0
[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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+9c1dcf141bc0875407c4eb36972857bd3db713e2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e35eb1f96edd445950f639e52d6ffa46573c44def534229d0e60d566555c8c30
[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" "e35eb1f96edd445950f639e52d6ffa46573c44def534229d0e60d566555c8c30", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e35eb1f96edd445950f639e52d6ffa46573c44def534229d0e60d566555c8c30", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e35eb1f96edd445950f639e52d6ffa46573c44def534229d0e60d566555c8c30", kill_on_drop: false }`
[INFO] [stdout] e35eb1f96edd445950f639e52d6ffa46573c44def534229d0e60d566555c8c30
[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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+9c1dcf141bc0875407c4eb36972857bd3db713e2" "check" "--frozen" "--all" "--all-targets" "--message-format=json", 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] 273c8a4a6d07b150f0e19b06c8d66d7d79005914d8bbc9808099bfd0028015c7
[INFO] running `Command { std: "docker" "start" "-a" "273c8a4a6d07b150f0e19b06c8d66d7d79005914d8bbc9808099bfd0028015c7", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]     Checking fastrand v1.4.0
[INFO] [stderr]     Checking fuzzcheck_traits v0.5.0
[INFO] [stderr]    Compiling decent-synquote-alternative v0.2.0
[INFO] [stderr]    Compiling fuzzcheck_mutators_derive v0.5.0
[INFO] [stderr]     Checking fuzzcheck_mutators v0.5.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: the feature `generic_associated_types` 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(generic_associated_types)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]   = note: see issue #44265 <https://github.com/rust-lang/rust/issues/44265> for more information
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `generic_associated_types` 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(generic_associated_types)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]   = note: see issue #44265 <https://github.com/rust-lang/rust/issues/44265> for more information
[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 12.73s
[INFO] running `Command { std: "docker" "inspect" "273c8a4a6d07b150f0e19b06c8d66d7d79005914d8bbc9808099bfd0028015c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "273c8a4a6d07b150f0e19b06c8d66d7d79005914d8bbc9808099bfd0028015c7", kill_on_drop: false }`
[INFO] [stdout] 273c8a4a6d07b150f0e19b06c8d66d7d79005914d8bbc9808099bfd0028015c7