[INFO] fetching crate mkbook 0.3.0...
[INFO] testing mkbook-0.3.0 against try#722e1797249a965b6335aebd65d777f917e498f1 for pr-91031
[INFO] extracting crate mkbook 0.3.0 into /workspace/builds/worker-23/source
[INFO] validating manifest of crates.io crate mkbook 0.3.0 on toolchain 722e1797249a965b6335aebd65d777f917e498f1
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mkbook 0.3.0
[INFO] finished tweaking crates.io crate mkbook 0.3.0
[INFO] tweaked toml for crates.io crate mkbook 0.3.0 written to /workspace/builds/worker-23/source/Cargo.toml
[INFO] crate crates.io crate mkbook 0.3.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded colored v1.9.0
[INFO] [stderr]   Downloaded askama_derive v0.8.0
[INFO] [stderr]   Downloaded askama v0.8.0
[INFO] [stderr]   Downloaded askama_shared v0.8.0
[INFO] [stderr]   Downloaded sass-sys v0.4.15
[INFO] [stderr]   Downloaded askama_escape v0.2.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-23/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-23/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@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a8dc178de023c460f87e3c00cdd339f539ab8728078f4385aee827411003e97d
[INFO] running `Command { std: "docker" "start" "-a" "a8dc178de023c460f87e3c00cdd339f539ab8728078f4385aee827411003e97d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a8dc178de023c460f87e3c00cdd339f539ab8728078f4385aee827411003e97d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a8dc178de023c460f87e3c00cdd339f539ab8728078f4385aee827411003e97d", kill_on_drop: false }`
[INFO] [stdout] a8dc178de023c460f87e3c00cdd339f539ab8728078f4385aee827411003e97d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-23/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-23/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:5736fa189c1c60b01babf4b8b698fe57b6ecc41933a7ff2e0b8d7a221459412b" "/opt/rustwide/cargo-home/bin/cargo" "+722e1797249a965b6335aebd65d777f917e498f1" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e1c0668e21625992d383d0ee4549af0828f191ef88475877fcbd39c0657decf8
[INFO] running `Command { std: "docker" "start" "-a" "e1c0668e21625992d383d0ee4549af0828f191ef88475877fcbd39c0657decf8", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.65
[INFO] [stderr]    Compiling proc-macro2 v1.0.6
[INFO] [stderr]    Compiling unicode-xid v0.2.0
[INFO] [stderr]    Compiling syn v1.0.8
[INFO] [stderr]    Compiling cfg-if v0.1.10
[INFO] [stderr]    Compiling serde v1.0.103
[INFO] [stderr]    Compiling memchr v2.2.1
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling byteorder v1.3.2
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling cc v1.0.47
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]    Compiling regex-syntax v0.6.12
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling pkg-config v0.3.17
[INFO] [stderr]    Compiling unicode-width v0.1.6
[INFO] [stderr]    Compiling quick-error v1.2.2
[INFO] [stderr]    Compiling rustc-demangle v0.1.16
[INFO] [stderr]    Compiling termcolor v1.0.5
[INFO] [stderr]    Compiling bindgen v0.50.1
[INFO] [stderr]    Compiling typenum v1.11.2
[INFO] [stderr]    Compiling getrandom v0.1.13
[INFO] [stderr]    Compiling ucd-trie v0.1.2
[INFO] [stderr]    Compiling crc32fast v1.2.0
[INFO] [stderr]    Compiling ppv-lite86 v0.2.6
[INFO] [stderr]    Compiling same-file v1.0.5
[INFO] [stderr]    Compiling ryu v1.0.2
[INFO] [stderr]    Compiling matches v0.1.8
[INFO] [stderr]    Compiling byte-tools v0.3.1
[INFO] [stderr]    Compiling maplit v1.0.2
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling lazycell v1.2.1
[INFO] [stderr]    Compiling smallvec v1.0.0
[INFO] [stderr]    Compiling slab v0.4.2
[INFO] [stderr]    Compiling adler32 v1.0.4
[INFO] [stderr]    Compiling humansize v1.1.0
[INFO] [stderr]    Compiling httparse v1.3.4
[INFO] [stderr]    Compiling safemem v0.3.3
[INFO] [stderr]    Compiling fnv v1.0.6
[INFO] [stderr]    Compiling askama_escape v0.2.0
[INFO] [stderr]    Compiling opaque-debug v0.2.3
[INFO] [stderr]    Compiling itoa v0.4.4
[INFO] [stderr]    Compiling unchecked-index v0.2.2
[INFO] [stderr]    Compiling xml-rs v0.8.0
[INFO] [stderr]    Compiling fake-simd v0.1.2
[INFO] [stderr]    Compiling percent-encoding v2.1.0
[INFO] [stderr]    Compiling linked-hash-map v0.5.2
[INFO] [stderr]    Compiling entities v1.0.1
[INFO] [stderr]    Compiling unicode_categories v0.1.1
[INFO] [stderr]    Compiling typed-arena v1.7.0
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling clang-sys v0.28.1
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling humantime v1.3.0
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling pest v2.1.2
[INFO] [stderr]    Compiling num-traits v0.2.10
[INFO] [stderr]    Compiling num-integer v0.1.41
[INFO] [stderr]    Compiling bincode v1.2.0
[INFO] [stderr]    Compiling line-wrap v0.1.1
[INFO] [stderr]    Compiling c2-chacha v0.2.3
[INFO] [stderr]    Compiling unicode-normalization v0.1.11
[INFO] [stderr]    Compiling nom v4.2.3
[INFO] [stderr]    Compiling block-padding v0.1.5
[INFO] [stderr]    Compiling unicode-bidi v0.3.4
[INFO] [stderr]    Compiling miniz_oxide v0.3.5
[INFO] [stderr]    Compiling walkdir v2.2.9
[INFO] [stderr]    Compiling yaml-rust v0.4.3
[INFO] [stderr]    Compiling crossbeam-channel v0.3.9
[INFO] [stderr]    Compiling backtrace-sys v0.1.32
[INFO] [stderr]    Compiling libloading v0.5.2
[INFO] [stderr]    Compiling idna v0.2.0
[INFO] [stderr]    Compiling pest_meta v2.1.2
[INFO] [stderr]    Compiling aho-corasick v0.7.6
[INFO] [stderr]    Compiling bstr v0.2.8
[INFO] [stderr]    Compiling twoway v0.2.1
[INFO] [stderr]    Compiling fxhash v0.2.1
[INFO] [stderr]    Compiling base64 v0.10.1
[INFO] [stderr]    Compiling url v2.1.0
[INFO] [stderr]    Compiling atty v0.2.13
[INFO] [stderr]    Compiling num_cpus v1.11.1
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling inotify-sys v0.1.3
[INFO] [stderr]    Compiling time v0.1.42
[INFO] [stderr]    Compiling filetime v0.2.8
[INFO] [stderr]    Compiling flate2 v1.0.13
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]    Compiling clap v2.33.0
[INFO] [stderr]    Compiling colored v1.9.0
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling bytes v0.4.12
[INFO] [stderr]    Compiling inotify v0.6.1
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.1
[INFO] [stderr]    Compiling sass-sys v0.4.15
[INFO] [stderr]    Compiling generic-array v0.12.3
[INFO] [stderr]    Compiling rand v0.7.2
[INFO] [stderr]    Compiling cexpr v0.3.6
[INFO] [stderr]    Compiling backtrace v0.3.40
[INFO] [stderr]    Compiling regex v1.3.1
[INFO] [stderr]    Compiling digest v0.8.1
[INFO] [stderr]    Compiling block-buffer v0.7.3
[INFO] [stderr]    Compiling failure v0.1.6
[INFO] [stderr]    Compiling sha-1 v0.8.1
[INFO] [stderr]    Compiling which v2.0.1
[INFO] [stderr]    Compiling chrono v0.4.10
[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-1.0.8/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="parsing"' --cfg 'feature="printing"' --cfg 'feature="proc-macro"' --cfg 'feature="quote"' --cfg 'feature="visit"' -C metadata=651338316a74ca7f -C extra-filename=-651338316a74ca7f --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-bd6e8e81ab7378d5.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-5a4cffc873d2b583.rmeta --extern unicode_xid=/opt/rustwide/target/debug/deps/libunicode_xid-1256a373de2a2211.rmeta --cap-lints allow --cap-lints=forbid` (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" "e1c0668e21625992d383d0ee4549af0828f191ef88475877fcbd39c0657decf8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e1c0668e21625992d383d0ee4549af0828f191ef88475877fcbd39c0657decf8", kill_on_drop: false }`
[INFO] [stdout] e1c0668e21625992d383d0ee4549af0828f191ef88475877fcbd39c0657decf8