[INFO] fetching crate howto 0.4.0...
[INFO] checking howto-0.4.0 against master#db1fb85cff63ad5fffe435e17128f99f9e1d970c for pr-89056
[INFO] extracting crate howto 0.4.0 into /workspace/builds/worker-54/source
[INFO] validating manifest of crates.io crate howto 0.4.0 on toolchain db1fb85cff63ad5fffe435e17128f99f9e1d970c
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate howto 0.4.0
[INFO] finished tweaking crates.io crate howto 0.4.0
[INFO] tweaked toml for crates.io crate howto 0.4.0 written to /workspace/builds/worker-54/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "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" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/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" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ca31fb7cb0be8fd60a64e4b2ec51c1f7a08de2ed34030f66059738779fc1b352
[INFO] running `Command { std: "docker" "start" "-a" "ca31fb7cb0be8fd60a64e4b2ec51c1f7a08de2ed34030f66059738779fc1b352", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ca31fb7cb0be8fd60a64e4b2ec51c1f7a08de2ed34030f66059738779fc1b352", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ca31fb7cb0be8fd60a64e4b2ec51c1f7a08de2ed34030f66059738779fc1b352", kill_on_drop: false }`
[INFO] [stdout] ca31fb7cb0be8fd60a64e4b2ec51c1f7a08de2ed34030f66059738779fc1b352
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+db1fb85cff63ad5fffe435e17128f99f9e1d970c" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d3128beab984bd67e44fe3db5954d56a37f1848712fe71aa869e4d17e8ff3276
[INFO] running `Command { std: "docker" "start" "-a" "d3128beab984bd67e44fe3db5954d56a37f1848712fe71aa869e4d17e8ff3276", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.102
[INFO] [stderr]    Compiling proc-macro2 v1.0.29
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling syn v1.0.76
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]    Compiling rand_core v0.4.2
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling siphasher v0.2.3
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]    Compiling string_cache_shared v0.3.0
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]     Checking pin-project-lite v0.1.12
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling itoa v0.4.8
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking new_debug_unreachable v1.0.4
[INFO] [stderr]     Checking mac v0.1.1
[INFO] [stderr]     Checking once_cell v1.8.0
[INFO] [stderr]     Checking precomputed-hash v0.1.1
[INFO] [stderr]     Checking tinyvec_macros v0.1.0
[INFO] [stderr]    Compiling procedural-masquerade v0.1.7
[INFO] [stderr]     Checking utf-8 v0.7.6
[INFO] [stderr]     Checking dtoa v0.4.8
[INFO] [stderr]     Checking nodrop v0.1.14
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]     Checking thin-slice v0.1.1
[INFO] [stderr]     Checking ego-tree v0.6.2
[INFO] [stderr]     Checking base64 v0.13.0
[INFO] [stderr]    Compiling openssl-sys v0.9.66
[INFO] [stderr]    Compiling futures-macro v0.3.17
[INFO] [stderr]    Compiling futures-util v0.3.17
[INFO] [stderr]    Compiling indexmap v1.7.0
[INFO] [stderr]    Compiling miniz_oxide v0.4.4
[INFO] [stderr]     Checking form_urlencoded v1.0.1
[INFO] [stderr]     Checking getopts v0.2.21
[INFO] [stderr]    Compiling serde v1.0.130
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]     Checking http-body v0.3.1
[INFO] [stderr]     Checking futures-channel v0.3.17
[INFO] [stderr]    Compiling phf_shared v0.7.24
[INFO] [stderr]     Checking futf v0.1.4
[INFO] [stderr]     Checking encoding_rs v0.8.28
[INFO] [stderr]     Checking servo_arc v0.1.1
[INFO] [stderr]     Checking tinyvec v1.4.0
[INFO] [stderr]    Compiling unicase v2.6.0
[INFO] [stderr]    Compiling openssl v0.10.36
[INFO] [stderr]    Compiling native-tls v0.2.8
[INFO] [stderr]    Compiling serde_json v1.0.68
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand_jitter v0.1.4
[INFO] [stderr]     Checking dtoa-short v0.3.3
[INFO] [stderr]     Checking serde_urlencoded v0.7.0
[INFO] [stderr]    Compiling rand_chacha v0.1.1
[INFO] [stderr]    Compiling rand_pcg v0.1.2
[INFO] [stderr]    Compiling rand v0.6.5
[INFO] [stderr]     Checking phf v0.7.24
[INFO] [stderr]     Checking iovec v0.1.4
[INFO] [stderr]     Checking net2 v0.2.37
[INFO] [stderr]     Checking signal-hook-registry v1.4.0
[INFO] [stderr]     Checking num_cpus v1.13.0
[INFO] [stderr]     Checking socket2 v0.3.19
[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 -C embed-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=adb60cc011dcdf6f -C extra-filename=-adb60cc011dcdf6f --out-dir /opt/rustwide/target/debug/deps -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-9484658faf025066.rmeta --extern quote=/opt/rustwide/target/debug/deps/libquote-b9bf6e54186ef813.rmeta --extern unicode_xid=/opt/rustwide/target/debug/deps/libunicode_xid-17df5e5ca0bb5bda.rmeta --cap-lints allow --cap-lints=forbid --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" "d3128beab984bd67e44fe3db5954d56a37f1848712fe71aa869e4d17e8ff3276", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d3128beab984bd67e44fe3db5954d56a37f1848712fe71aa869e4d17e8ff3276", kill_on_drop: false }`
[INFO] [stdout] d3128beab984bd67e44fe3db5954d56a37f1848712fe71aa869e4d17e8ff3276