[INFO] fetching crate slack-gc 1.0.1...
[INFO] testing slack-gc-1.0.1 against 1.55.0 for beta-1.56-1
[INFO] extracting crate slack-gc 1.0.1 into /workspace/builds/worker-34/source
[INFO] validating manifest of crates.io crate slack-gc 1.0.1 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 slack-gc 1.0.1
[INFO] finished tweaking crates.io crate slack-gc 1.0.1
[INFO] tweaked toml for crates.io crate slack-gc 1.0.1 written to /workspace/builds/worker-34/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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-34/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-34/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] abbbbe19ede5b715a347e4c441d2d7bfcfe7388f2c8369d699bc9139127fbed1
[INFO] running `Command { std: "docker" "start" "-a" "abbbbe19ede5b715a347e4c441d2d7bfcfe7388f2c8369d699bc9139127fbed1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "abbbbe19ede5b715a347e4c441d2d7bfcfe7388f2c8369d699bc9139127fbed1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "abbbbe19ede5b715a347e4c441d2d7bfcfe7388f2c8369d699bc9139127fbed1", kill_on_drop: false }`
[INFO] [stdout] abbbbe19ede5b715a347e4c441d2d7bfcfe7388f2c8369d699bc9139127fbed1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-34/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-34/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] 63e193319f4d46f9fa313448122cd897af54b502a228d189960debfe53f38c32
[INFO] running `Command { std: "docker" "start" "-a" "63e193319f4d46f9fa313448122cd897af54b502a228d189960debfe53f38c32", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.0.1
[INFO] [stderr]    Compiling libc v0.2.101
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling futures v0.1.31
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling slab v0.4.4
[INFO] [stderr]    Compiling byteorder v1.4.3
[INFO] [stderr]    Compiling cc v1.0.70
[INFO] [stderr]    Compiling fnv v1.0.7
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]    Compiling pkg-config v0.3.19
[INFO] [stderr]    Compiling openssl v0.9.24
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling foreign-types-shared v0.1.1
[INFO] [stderr]    Compiling tinyvec_macros v0.1.0
[INFO] [stderr]    Compiling crossbeam-utils v0.8.5
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling httparse v1.5.1
[INFO] [stderr]    Compiling bitflags v0.9.1
[INFO] [stderr]    Compiling percent-encoding v1.0.1
[INFO] [stderr]    Compiling serde v1.0.130
[INFO] [stderr]    Compiling scoped-tls v0.1.2
[INFO] [stderr]    Compiling try-lock v0.1.0
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.5
[INFO] [stderr]    Compiling memchr v2.4.1
[INFO] [stderr]    Compiling mime v0.3.16
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling crc32fast v1.2.1
[INFO] [stderr]    Compiling lazy_static v0.2.11
[INFO] [stderr]    Compiling matches v0.1.9
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling unicode-bidi v0.3.6
[INFO] [stderr]    Compiling safemem v0.3.3
[INFO] [stderr]    Compiling rayon-core v1.9.1
[INFO] [stderr]    Compiling encoding_rs v0.8.28
[INFO] [stderr]    Compiling itoa v0.4.8
[INFO] [stderr]    Compiling language-tags v0.2.2
[INFO] [stderr]    Compiling serde_json v1.0.67
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling rle-decode-fast v1.0.1
[INFO] [stderr]    Compiling gimli v0.25.0
[INFO] [stderr]    Compiling adler v1.0.2
[INFO] [stderr]    Compiling serde_derive v1.0.130
[INFO] [stderr]    Compiling dtoa v0.4.8
[INFO] [stderr]    Compiling take_mut v0.2.2
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling adler32 v1.2.0
[INFO] [stderr]    Compiling rustc-demangle v0.1.21
[INFO] [stderr]    Compiling vec_map v0.8.2
[INFO] [stderr]    Compiling bitflags v1.3.2
[INFO] [stderr]    Compiling strsim v0.8.0
[INFO] [stderr]    Compiling ansi_term v0.11.0
[INFO] [stderr]    Compiling either v1.6.1
[INFO] [stderr]    Compiling tinyvec v1.3.1
[INFO] [stderr]    Compiling foreign-types v0.3.2
[INFO] [stderr]    Compiling lock_api v0.3.4
[INFO] [stderr]    Compiling crossbeam-utils v0.7.2
[INFO] [stderr]    Compiling memoffset v0.5.6
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.2
[INFO] [stderr]    Compiling memoffset v0.6.4
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling miniz_oxide v0.4.4
[INFO] [stderr]    Compiling rayon v1.5.1
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling base64 v0.9.3
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling getopts v0.2.21
[INFO] [stderr]    Compiling smallvec v0.6.14
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling unicase v2.6.0
[INFO] [stderr]    Compiling libflate v0.1.27
[INFO] [stderr]    Compiling crossbeam-channel v0.5.1
[INFO] [stderr]    Compiling synstructure v0.12.5
[INFO] [stderr]    Compiling openssl-sys v0.9.66
[INFO] [stderr]    Compiling backtrace v0.3.61
[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-1.0.76/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="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="quote"' --cfg 'feature="visit"' -C metadata=31330b1cc36735b4 -C extra-filename=-31330b1cc36735b4 --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-06e97d6f0dfb172f.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-1b457121b46aa6b0.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" "63e193319f4d46f9fa313448122cd897af54b502a228d189960debfe53f38c32", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "63e193319f4d46f9fa313448122cd897af54b502a228d189960debfe53f38c32", kill_on_drop: false }`
[INFO] [stdout] 63e193319f4d46f9fa313448122cd897af54b502a228d189960debfe53f38c32