[INFO] fetching crate mbus 0.3.5...
[INFO] testing mbus-0.3.5 against 1.55.0 for beta-1.56-1
[INFO] extracting crate mbus 0.3.5 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate mbus 0.3.5 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mbus 0.3.5
[INFO] finished tweaking crates.io crate mbus 0.3.5
[INFO] tweaked toml for crates.io crate mbus 0.3.5 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate mbus 0.3.5 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--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-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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7b49f4886b9d137b70a3cb11415f20132977677b0982da2a88ed09f3f3d7381e
[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" "7b49f4886b9d137b70a3cb11415f20132977677b0982da2a88ed09f3f3d7381e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7b49f4886b9d137b70a3cb11415f20132977677b0982da2a88ed09f3f3d7381e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b49f4886b9d137b70a3cb11415f20132977677b0982da2a88ed09f3f3d7381e", kill_on_drop: false }`
[INFO] [stdout] 7b49f4886b9d137b70a3cb11415f20132977677b0982da2a88ed09f3f3d7381e
[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=warn" "-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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 7822c23c99c3e12f6f1ca6ebee040fdf49b20f99b68503e5201a6354825f064c
[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" "7822c23c99c3e12f6f1ca6ebee040fdf49b20f99b68503e5201a6354825f064c", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.94
[INFO] [stderr]    Compiling syn v1.0.72
[INFO] [stderr]    Compiling serde_derive v1.0.125
[INFO] [stderr]    Compiling serde v1.0.125
[INFO] [stderr]    Compiling unicode-xid v0.0.3
[INFO] [stderr]    Compiling openssl v0.10.34
[INFO] [stderr]    Compiling bitflags v0.5.0
[INFO] [stderr]    Compiling pnet_base v0.26.0
[INFO] [stderr]    Compiling modifier v0.1.0
[INFO] [stderr]    Compiling async-trait v0.1.50
[INFO] [stderr]    Compiling pnet v0.26.0
[INFO] [stderr]    Compiling nix v0.11.1
[INFO] [stderr]    Compiling groupable v0.2.0
[INFO] [stderr]    Compiling rustc-demangle v0.1.19
[INFO] [stderr]    Compiling ascii v0.8.7
[INFO] [stderr]    Compiling chunked_transfer v0.3.1
[INFO] [stderr]    Compiling openssl-sys v0.9.63
[INFO] [stderr]    Compiling syntex_pos v0.42.0
[INFO] [stderr]    Compiling futures-channel v0.3.14
[INFO] [stderr]    Compiling unsafe-any v0.4.2
[INFO] [stderr]    Compiling http-body v0.3.1
[INFO] [stderr]    Compiling tracing v0.1.26
[INFO] [stderr]    Compiling buf_redux v0.8.4
[INFO] [stderr]    Compiling twoway v0.1.8
[INFO] [stderr]    Compiling idna v0.1.5
[INFO] [stderr]    Compiling pnet_macros_support v0.26.0
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]    Compiling typemap v0.3.3
[INFO] [stderr]    Compiling phf_shared v0.7.24
[INFO] [stderr]    Compiling tokio-timer v0.2.13
[INFO] [stderr]    Compiling phf v0.7.24
[INFO] [stderr]    Compiling plugin v0.2.6
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling net2 v0.2.37
[INFO] [stderr]    Compiling syntex_errors v0.42.0
[INFO] [stderr]    Compiling time v0.1.43
[INFO] [stderr]    Compiling getrandom v0.2.2
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]    Compiling socket2 v0.3.19
[INFO] [stderr]    Compiling pnet_sys v0.26.0
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling signal-hook-registry v1.3.0
[INFO] [stderr]    Compiling backtrace v0.3.58
[INFO] [stderr]    Compiling nix v0.14.1
[INFO] [stderr]    Compiling url v1.7.2
[INFO] [stderr]    Compiling hyper-openssl v0.8.1
[INFO] [stderr]    Compiling native-tls v0.2.7
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]    Compiling rand_core v0.6.2
[INFO] [stderr]    Compiling tokio-threadpool v0.1.18
[INFO] [stderr]    Compiling signal-hook v0.1.17
[INFO] [stderr]    Compiling mio v0.6.23
[INFO] [stderr]    Compiling syntex_syntax v0.42.0
[INFO] [stderr]    Compiling env_logger v0.7.1
[INFO] [stderr]    Compiling error-chain v0.12.4
[INFO] [stderr]    Compiling tokio-io v0.1.13
[INFO] [stderr]    Compiling hyper-old-types v0.11.0
[INFO] [stderr]    Compiling rand_chacha v0.3.0
[INFO] [stderr]    Compiling hyper v0.10.16
[INFO] [stderr]    Compiling mio-uds v0.6.8
[INFO] [stderr]    Compiling phf_generator v0.7.24
[INFO] [stderr]    Compiling rand v0.8.3
[INFO] [stderr]    Compiling tokio-reactor v0.1.12
[INFO] [stderr]    Compiling tokio-codec v0.1.2
[INFO] [stderr]    Compiling tokio-fs v0.1.7
[INFO] [stderr]    Compiling phf_codegen v0.7.24
[INFO] [stderr]    Compiling mime_guess v1.8.8
[INFO] [stderr]    Compiling tokio-udp v0.1.6
[INFO] [stderr]    Compiling tokio-tcp v0.1.4
[INFO] [stderr]    Compiling tokio-uds v0.2.7
[INFO] [stderr]    Compiling tokio v0.1.22
[INFO] [stderr]    Compiling tempfile v3.2.0
[INFO] [stderr] error: could not compile `syn`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustc --crate-name syn --edition=2018 /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/syn-1.0.72/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata,link -C embed-bitcode=no -C debuginfo=2 --cfg 'feature="clone-impls"' --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="full"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="quote"' --cfg 'feature="visit-mut"' -C metadata=4335378c5c6560ea -C extra-filename=-4335378c5c6560ea --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-8ff1f8fbe76adf54.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-70a9d80307bde4de.rmeta --extern unicode_xid=/opt/rustwide/target/debug/deps/libunicode_xid-5ecee5fca1210f52.rmeta --cap-lints allow --cap-lints=warn --cfg syn_disable_nightly_tests` (signal: 9, SIGKILL: kill)
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "7822c23c99c3e12f6f1ca6ebee040fdf49b20f99b68503e5201a6354825f064c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7822c23c99c3e12f6f1ca6ebee040fdf49b20f99b68503e5201a6354825f064c", kill_on_drop: false }`
[INFO] [stdout] 7822c23c99c3e12f6f1ca6ebee040fdf49b20f99b68503e5201a6354825f064c