[INFO] fetching crate earbuds 0.1.7...
[INFO] testing earbuds-0.1.7 against 1.49.0 for beta-1.50-1
[INFO] extracting crate earbuds 0.1.7 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate earbuds 0.1.7 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate earbuds 0.1.7
[INFO] finished tweaking crates.io crate earbuds 0.1.7
[INFO] tweaked toml for crates.io crate earbuds 0.1.7 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate crates.io crate earbuds 0.1.7 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "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-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "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] 35fcbe81a554c7f091b93e22f81fc89f83624c63686b886e1f78e7c2a3e012d3
[INFO] running `Command { std: "docker" "start" "-a" "35fcbe81a554c7f091b93e22f81fc89f83624c63686b886e1f78e7c2a3e012d3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "35fcbe81a554c7f091b93e22f81fc89f83624c63686b886e1f78e7c2a3e012d3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "35fcbe81a554c7f091b93e22f81fc89f83624c63686b886e1f78e7c2a3e012d3", kill_on_drop: false }`
[INFO] [stdout] 35fcbe81a554c7f091b93e22f81fc89f83624c63686b886e1f78e7c2a3e012d3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--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] e709d51cb6b07a402089eea98ce3b9917bed66f741829de6f5347d6dfd29349f
[INFO] running `Command { std: "docker" "start" "-a" "e709d51cb6b07a402089eea98ce3b9917bed66f741829de6f5347d6dfd29349f", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]    Compiling syn v1.0.50
[INFO] [stderr]    Compiling log v0.4.11
[INFO] [stderr]    Compiling futures-core v0.3.8
[INFO] [stderr]    Compiling cache-padded v1.1.1
[INFO] [stderr]    Compiling parking v2.0.0
[INFO] [stderr]    Compiling waker-fn v1.1.0
[INFO] [stderr]    Compiling fastrand v1.4.0
[INFO] [stderr]    Compiling pin-project-lite v0.1.11
[INFO] [stderr]    Compiling futures-io v0.3.8
[INFO] [stderr]    Compiling unicode-segmentation v1.7.0
[INFO] [stderr]    Compiling const_fn v0.4.3
[INFO] [stderr]    Compiling ident_case v1.0.1
[INFO] [stderr]    Compiling vec-arena v1.0.0
[INFO] [stderr]    Compiling async-task v4.0.3
[INFO] [stderr]    Compiling event-listener v2.5.1
[INFO] [stderr]    Compiling serde v1.0.117
[INFO] [stderr]    Compiling atomic-waker v1.0.0
[INFO] [stderr]    Compiling nix v0.13.1
[INFO] [stderr]    Compiling error-chain v0.11.0
[INFO] [stderr]    Compiling hashbrown v0.9.1
[INFO] [stderr]    Compiling serde_derive v1.0.117
[INFO] [stderr]    Compiling os_str_bytes v2.4.0
[INFO] [stderr]    Compiling serde_json v1.0.59
[INFO] [stderr]    Compiling strsim v0.10.0
[INFO] [stderr]    Compiling glob v0.3.0
[INFO] [stderr]    Compiling itoa v0.4.6
[INFO] [stderr]    Compiling proc-macro2 v0.3.8
[INFO] [stderr]    Compiling libdbus-sys v0.2.1
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling crossbeam-utils v0.8.0
[INFO] [stderr]    Compiling libpulse-sys v1.13.3
[INFO] [stderr]    Compiling proc-macro2 v0.2.3
[INFO] [stderr]    Compiling indexmap v1.6.0
[INFO] [stderr]    Compiling error-chain v0.12.4
[INFO] [stderr]    Compiling concurrent-queue v1.2.2
[INFO] [stderr]    Compiling addr2line v0.14.0
[INFO] [stderr]    Compiling textwrap v0.12.1
[INFO] [stderr]    Compiling async-mutex v1.4.0
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling syn v0.11.11
[INFO] [stderr]    Compiling quote v0.5.2
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling futures-lite v1.11.2
[INFO] [stderr]    Compiling async-channel v1.5.1
[INFO] [stderr]    Compiling quote v0.4.2
[INFO] [stderr]    Compiling syn v0.13.11
[INFO] [stderr]    Compiling kv-log-macro v1.0.7
[INFO] [stderr]    Compiling syn v0.12.15
[INFO] [stderr]    Compiling async-executor v1.4.0
[INFO] [stderr]    Compiling blocking v1.0.2
[INFO] [stderr]    Compiling derive_is_enum_variant v0.1.1
[INFO] [stderr]    Compiling nb-connect v1.0.2
[INFO] [stderr]    Compiling polling v2.0.2
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling net2 v0.2.35
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling dbus v0.8.4
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling backtrace v0.3.55
[INFO] [stderr]    Compiling dbus v0.6.5
[INFO] [stderr]    Compiling nix v0.17.0
[INFO] [stderr]    Compiling nix v0.19.0
[INFO] [stderr]    Compiling async-io v1.2.0
[INFO] [stderr]    Compiling mio v0.6.22
[INFO] [stderr]    Compiling libpulse-binding v2.16.3
[INFO] [stderr]    Compiling enum-kinds v0.4.1
[INFO] [stderr]    Compiling async-global-executor v1.4.3
[INFO] [stderr]    Compiling rust-pulsectl v0.2.6
[INFO] [stderr]    Compiling darling_core v0.5.0
[INFO] [stderr]    Compiling toml v0.5.7
[INFO] [stderr]    Compiling blurz v0.4.0
[INFO] [stderr]    Compiling synstructure v0.12.4
[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-1.0.50/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi,artifacts --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="extra-traits"' --cfg 'feature="full"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="quote"' --cfg 'feature="visit"' -C metadata=2739163d84058fe6 -C extra-filename=-2739163d84058fe6 --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-b8449736663a1660.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-ac1b49ec88ef2fec.rmeta --extern unicode_xid=/opt/rustwide/target/debug/deps/libunicode_xid-1c0accd586890c80.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" "e709d51cb6b07a402089eea98ce3b9917bed66f741829de6f5347d6dfd29349f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e709d51cb6b07a402089eea98ce3b9917bed66f741829de6f5347d6dfd29349f", kill_on_drop: false }`
[INFO] [stdout] e709d51cb6b07a402089eea98ce3b9917bed66f741829de6f5347d6dfd29349f