[INFO] fetching crate ss-dom-tree 0.1.1...
[INFO] checking ss-dom-tree-0.1.1 against master#36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923 for pr-81863
[INFO] extracting crate ss-dom-tree 0.1.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate ss-dom-tree 0.1.1 on toolchain 36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ss-dom-tree 0.1.1
[INFO] finished tweaking crates.io crate ss-dom-tree 0.1.1
[INFO] tweaked toml for crates.io crate ss-dom-tree 0.1.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "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" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "fetch" "--locked" "--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-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 418c0ef3675ace28c6edf8fc87d54277197ee705178fdc896130a7d14708cc51
[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" "418c0ef3675ace28c6edf8fc87d54277197ee705178fdc896130a7d14708cc51", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "418c0ef3675ace28c6edf8fc87d54277197ee705178fdc896130a7d14708cc51", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "418c0ef3675ace28c6edf8fc87d54277197ee705178fdc896130a7d14708cc51", kill_on_drop: false }`
[INFO] [stdout] 418c0ef3675ace28c6edf8fc87d54277197ee705178fdc896130a7d14708cc51
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "rustops/crates-build-env@sha256:21f1ed92105a0ef9b0d27ad8bdeb7f36f9f01ac17fffe3a3f3dc5241fc25d8f4" "/opt/rustwide/cargo-home/bin/cargo" "+36ecbc94eb6be90bc38b2d0fdd4bfac3f34d9923" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 08de0bf190cc749153d0ca6363458bee38c56875c36ddec7d50ca72b27f02934
[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" "08de0bf190cc749153d0ca6363458bee38c56875c36ddec7d50ca72b27f02934", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]     Checking rand_core v0.4.2
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling autocfg v0.1.7
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling wasm-bindgen-shared v0.2.70
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling libc v0.2.85
[INFO] [stderr]    Compiling bumpalo v3.6.0
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling wasm-bindgen v0.2.70
[INFO] [stderr]    Compiling serde_derive v1.0.123
[INFO] [stderr]     Checking scopeguard v0.3.3
[INFO] [stderr]    Compiling serde v1.0.123
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]     Checking itoa v0.4.7
[INFO] [stderr]     Checking either v1.6.1
[INFO] [stderr]     Checking cfg-if v0.1.10
[INFO] [stderr]     Checking lock_api v0.1.5
[INFO] [stderr]     Checking rand_core v0.3.1
[INFO] [stderr]     Checking rand_jitter v0.1.4
[INFO] [stderr]     Checking rand_isaac v0.1.1
[INFO] [stderr]     Checking rand_hc v0.1.0
[INFO] [stderr]     Checking rand_xorshift v0.1.1
[INFO] [stderr]     Checking itertools v0.8.2
[INFO] [stderr]    Compiling parking_lot_core v0.4.0
[INFO] [stderr]     Checking Inflector v0.11.4
[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 smallvec v0.6.14
[INFO] [stderr]    Compiling quote v1.0.8
[INFO] [stderr]     Checking rand_os v0.1.3
[INFO] [stderr]    Compiling syn v1.0.60
[INFO] [stderr]     Checking parking_lot v0.7.1
[INFO] [stderr]     Checking once_cell v0.1.8
[INFO] [stderr]     Checking cached v0.8.1
[INFO] [stderr]    Compiling wasm-bindgen-backend v0.2.70
[INFO] [stderr]    Compiling wasm-bindgen-macro-support v0.2.70
[INFO] [stderr]    Compiling wasm-bindgen-macro v0.2.70
[INFO] [stderr]     Checking js-sys v0.3.47
[INFO] [stderr]     Checking console_error_panic_hook v0.1.6
[INFO] [stderr]     Checking web-sys v0.3.47
[INFO] [stderr]     Checking serde_json v1.0.62
[INFO] [stderr]     Checking ss-web-utils v0.1.1
[INFO] [stderr]     Checking ss-trees v0.1.1
[INFO] [stdout] error[E0635]: unknown feature `vec_remove_item`
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/ss-trees-0.1.1/src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(vec_remove_item)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0635`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `ss-trees`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "08de0bf190cc749153d0ca6363458bee38c56875c36ddec7d50ca72b27f02934", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "08de0bf190cc749153d0ca6363458bee38c56875c36ddec7d50ca72b27f02934", kill_on_drop: false }`
[INFO] [stdout] 08de0bf190cc749153d0ca6363458bee38c56875c36ddec7d50ca72b27f02934