[INFO] fetching crate mber 0.1.8...
[INFO] documenting mber-0.1.8 against master#394e1b40d264aa6928811919c1124fa248e7d802 for pr-73566
[INFO] extracting crate mber 0.1.8 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate mber 0.1.8 on toolchain 394e1b40d264aa6928811919c1124fa248e7d802
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mber 0.1.8
[INFO] finished tweaking crates.io crate mber 0.1.8
[INFO] tweaked toml for crates.io crate mber 0.1.8 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate crates.io crate mber 0.1.8 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "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-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d71988b6f08f631a48ff36a84fa7ad0eaba5987d134df8537f39e9de7750ff25
[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" "d71988b6f08f631a48ff36a84fa7ad0eaba5987d134df8537f39e9de7750ff25", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d71988b6f08f631a48ff36a84fa7ad0eaba5987d134df8537f39e9de7750ff25", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d71988b6f08f631a48ff36a84fa7ad0eaba5987d134df8537f39e9de7750ff25", kill_on_drop: false }`
[INFO] [stdout] d71988b6f08f631a48ff36a84fa7ad0eaba5987d134df8537f39e9de7750ff25
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "doc" "--frozen" "--no-deps" "--document-private-items" "--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] 9df5e9454c867db3ad8fe176196975d6d1faf40dd4b7f21226eb9fb6c86f48f5
[INFO] running `Command { std: "docker" "start" "-a" "9df5e9454c867db3ad8fe176196975d6d1faf40dd4b7f21226eb9fb6c86f48f5", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling proc-macro2 v1.0.6
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]    Compiling serde v1.0.102
[INFO] [stderr]    Compiling ryu v1.0.2
[INFO] [stderr]     Checking either v1.5.3
[INFO] [stderr]    Compiling string_cache_shared v0.3.0
[INFO] [stderr]    Compiling itoa v0.4.4
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking new_debug_unreachable v1.0.3
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling same-file v1.0.5
[INFO] [stderr]     Checking regex-syntax v0.6.12
[INFO] [stderr]     Checking bit-vec v0.5.1
[INFO] [stderr]     Checking adler32 v1.0.4
[INFO] [stderr]     Checking rle-decode-fast v1.0.1
[INFO] [stderr]     Checking yansi v0.5.0
[INFO] [stderr]     Checking crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling crossbeam-utils v0.7.0
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.0
[INFO] [stderr]    Compiling indexmap v1.3.0
[INFO] [stderr]     Checking thread_local v0.3.6
[INFO] [stderr]    Compiling phf_shared v0.7.24
[INFO] [stderr]     Checking tokio-sync v0.1.7
[INFO] [stderr]     Checking futf v0.1.4
[INFO] [stderr]    Compiling walkdir v2.2.9
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]     Checking bit-set v0.5.1
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]     Checking crc32fast v1.2.0
[INFO] [stderr]     Checking log v0.3.9
[INFO] [stderr]     Checking want v0.2.0
[INFO] [stderr]    Compiling memoffset v0.5.3
[INFO] [stderr]    Compiling hyper v0.12.35
[INFO] [stderr]     Checking phf v0.7.24
[INFO] [stderr]     Checking libflate v0.1.27
[INFO] [stderr]     Checking tendril v0.4.1
[INFO] [stderr]     Checking tokio-executor v0.1.8
[INFO] [stderr]     Checking crossbeam-queue v0.1.2
[INFO] [stderr]     Checking tokio-timer v0.2.11
[INFO] [stderr]     Checking tokio-current-thread v0.1.6
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]     Checking aho-corasick v0.7.6
[INFO] [stderr]     Checking crossbeam-deque v0.7.2
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling rand_os v0.1.3
[INFO] [stderr]    Compiling num_cpus v1.11.1
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.33
[INFO] [stderr]     Checking parking_lot_core v0.6.2
[INFO] [stderr]     Checking time v0.1.42
[INFO] [stderr]     Checking bytes v0.4.12
[INFO] [stderr]     Checking futures-cpupool v0.1.8
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]     Checking tokio-threadpool v0.1.16
[INFO] [stderr]    Compiling sass-sys v0.4.14
[INFO] [stderr]     Checking mio v0.6.19
[INFO] [stderr]     Checking parking_lot v0.9.0
[INFO] [stderr]     Checking tokio-io v0.1.12
[INFO] [stderr]     Checking http v0.1.19
[INFO] [stderr]     Checking tokio-buf v0.1.1
[INFO] [stderr]     Checking string v0.2.1
[INFO] [stderr]     Checking tokio-reactor v0.1.10
[INFO] [stderr]     Checking regex v1.3.1
[INFO] [stderr] error: could not compile `syn`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustc --crate-name syn /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/syn-0.15.44/src/lib.rs --error-format=json --json=diagnostic-rendered-ansi --crate-type lib --emit=dep-info,metadata,link -Cembed-bitcode=no -C debuginfo=2 --cfg 'feature="clone-impls"' --cfg 'feature="default"' --cfg 'feature="derive"' --cfg 'feature="extra-traits"' --cfg 'feature="fold"' --cfg 'feature="full"' --cfg 'feature="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="quote"' -C metadata=ff39c6b2a0bb168b -C extra-filename=-ff39c6b2a0bb168b --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-8f5127d3b79dbf84.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-dbccb4b92c5e0bf6.rmeta --extern unicode_xid=/opt/rustwide/target/debug/deps/libunicode_xid-b99289dd4881e0db.rmeta --cap-lints allow --cfg syn_can_match_trailing_dollar --cfg syn_can_use_thread_id --cfg syn_can_use_associated_constants --cfg syn_can_call_macro_by_path` (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" "9df5e9454c867db3ad8fe176196975d6d1faf40dd4b7f21226eb9fb6c86f48f5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9df5e9454c867db3ad8fe176196975d6d1faf40dd4b7f21226eb9fb6c86f48f5", kill_on_drop: false }`
[INFO] [stdout] 9df5e9454c867db3ad8fe176196975d6d1faf40dd4b7f21226eb9fb6c86f48f5