[INFO] cloning repository https://github.com/rubytogether/kirby
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/rubytogether/kirby" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frubytogether%2Fkirby", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frubytogether%2Fkirby'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9495d6a4fa5c64bdd42172396b089b56096e0c18
[INFO] testing rubytogether/kirby against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frubytogether%2Fkirby" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/rubytogether/kirby 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 git repo https://github.com/rubytogether/kirby
[INFO] disabled cargo feature 'default-run' from git repo https://github.com/rubytogether/kirby
[INFO] finished tweaking git repo https://github.com/rubytogether/kirby
[INFO] tweaked toml for git repo https://github.com/rubytogether/kirby written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/rubytogether/kirby already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 21c8397154bea93682af8806df02576e3cf1805ee22dfed119abe5db6cbc0168
[INFO] running `Command { std: "docker" "start" "-a" "21c8397154bea93682af8806df02576e3cf1805ee22dfed119abe5db6cbc0168", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "21c8397154bea93682af8806df02576e3cf1805ee22dfed119abe5db6cbc0168", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "21c8397154bea93682af8806df02576e3cf1805ee22dfed119abe5db6cbc0168", kill_on_drop: false }`
[INFO] [stdout] 21c8397154bea93682af8806df02576e3cf1805ee22dfed119abe5db6cbc0168
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] dbfca23117a1a30ee705a2f2894cd361239275eea1ae7c266f5abbe4adf95ad7
[INFO] running `Command { std: "docker" "start" "-a" "dbfca23117a1a30ee705a2f2894cd361239275eea1ae7c266f5abbe4adf95ad7", kill_on_drop: false }`
[INFO] [stderr]    Compiling serde v1.0.75
[INFO] [stderr]    Compiling cc v1.0.22
[INFO] [stderr]    Compiling futures v0.1.24
[INFO] [stderr]    Compiling proc-macro2 v0.4.13
[INFO] [stderr]    Compiling ryu v0.2.5
[INFO] [stderr]    Compiling httparse v1.3.2
[INFO] [stderr]    Compiling pulldown-cmark v0.1.2
[INFO] [stderr]    Compiling indexmap v1.0.1
[INFO] [stderr]    Compiling same-file v1.0.3
[INFO] [stderr]    Compiling arrayref v0.3.5
[INFO] [stderr]    Compiling byte-tools v0.2.0
[INFO] [stderr]    Compiling constant_time_eq v0.1.3
[INFO] [stderr]    Compiling regex v1.0.4
[INFO] [stderr]    Compiling md5 v0.3.8
[INFO] [stderr]    Compiling reexport-proc-macro v1.0.5
[INFO] [stderr]    Compiling array-macro v1.0.2
[INFO] [stderr]    Compiling argparse v0.2.2
[INFO] [stderr]    Compiling log v0.4.5
[INFO] [stderr]    Compiling unreachable v1.0.0
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling crossbeam-utils v0.2.2
[INFO] [stderr]    Compiling base64 v0.9.3
[INFO] [stderr]    Compiling nom v4.0.0
[INFO] [stderr]    Compiling tempdir v0.3.7
[INFO] [stderr]    Compiling block-buffer v0.3.3
[INFO] [stderr]    Compiling lock_api v0.1.3
[INFO] [stderr]    Compiling walkdir v2.2.5
[INFO] [stderr]    Compiling smallvec v0.6.5
[INFO] [stderr]    Compiling mio v0.6.16
[INFO] [stderr]    Compiling syn v0.13.11
[INFO] [stderr]    Compiling generic-array v0.9.0
[INFO] [stderr]    Compiling pest_derive v1.0.8
[INFO] [stderr]    Compiling url v1.7.1
[INFO] [stderr]    Compiling crossbeam-epoch v0.5.2
[INFO] [stderr]    Compiling crossbeam-epoch v0.3.1
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]    Compiling digest v0.7.6
[INFO] [stderr]    Compiling crypto-mac v0.5.2
[INFO] [stderr]    Compiling crossbeam-deque v0.6.1
[INFO] [stderr]    Compiling crossbeam-deque v0.2.0
[INFO] [stderr]    Compiling mio-uds v0.6.7
[INFO] [stderr]    Compiling tokio-executor v0.1.4
[INFO] [stderr]    Compiling futures-cpupool v0.1.8
[INFO] [stderr]    Compiling want v0.0.6
[INFO] [stderr]    Compiling tower-service v0.1.0
[INFO] [stderr]    Compiling hmac v0.5.0
[INFO] [stderr]    Compiling sha2 v0.7.1
[INFO] [stderr]    Compiling quote v0.6.8
[INFO] [stderr]    Compiling rayon-core v1.4.1
[INFO] [stderr]    Compiling backtrace-sys v0.1.24
[INFO] [stderr]    Compiling ring v0.13.2
[INFO] [stderr]    Compiling libz-sys v1.0.20
[INFO] [stderr]    Compiling tokio-threadpool v0.1.6
[INFO] [stderr]    Compiling tokio-current-thread v0.1.1
[INFO] [stderr]    Compiling tokio-timer v0.2.6
[INFO] [stderr]    Compiling serde_derive_internals v0.23.1
[INFO] [stderr]    Compiling syn v0.14.9
[INFO] [stderr]    Compiling rayon v1.0.2
[INFO] [stderr]    Compiling flate2 v1.0.2
[INFO] [stderr]    Compiling backtrace v0.3.9
[INFO] [stderr]    Compiling error-chain v0.11.0
[INFO] [stderr]    Compiling serde_schema_derive v0.1.0 (https://github.com/srijs/rust-serde-schema#da935d38)
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling bytes v0.4.10
[INFO] [stderr]    Compiling serde_json v1.0.26
[INFO] [stderr]    Compiling chrono v0.4.6
[INFO] [stderr]    Compiling serde_bytes v0.10.4
[INFO] [stderr]    Compiling hashbrown v0.1.6
[INFO] [stderr]    Compiling synstructure v0.9.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/hashbrown-0.1.6/src/lib.rs:15:5
[INFO] [stdout]    |
[INFO] [stdout] 15 |     feature(alloc, alloc_layout_extra, allocator_api, ptr_offset_from, test, core_intrinsics)
[INFO] [stdout]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `hashbrown` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "dbfca23117a1a30ee705a2f2894cd361239275eea1ae7c266f5abbe4adf95ad7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "dbfca23117a1a30ee705a2f2894cd361239275eea1ae7c266f5abbe4adf95ad7", kill_on_drop: false }`
[INFO] [stdout] dbfca23117a1a30ee705a2f2894cd361239275eea1ae7c266f5abbe4adf95ad7