[INFO] fetching crate quix 0.0.6...
[INFO] testing quix-0.0.6 against 1.49.0 for beta-1.50-1
[INFO] extracting crate quix 0.0.6 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate quix 0.0.6 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate quix 0.0.6
[INFO] finished tweaking crates.io crate quix 0.0.6
[INFO] tweaked toml for crates.io crate quix 0.0.6 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] crate crates.io crate quix 0.0.6 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--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-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] a1dd679792a10a5b3b5beb4898127bd84059fdcc5338d20c362974d4fe765a22
[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" "a1dd679792a10a5b3b5beb4898127bd84059fdcc5338d20c362974d4fe765a22", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "a1dd679792a10a5b3b5beb4898127bd84059fdcc5338d20c362974d4fe765a22", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a1dd679792a10a5b3b5beb4898127bd84059fdcc5338d20c362974d4fe765a22", kill_on_drop: false }`
[INFO] [stdout] a1dd679792a10a5b3b5beb4898127bd84059fdcc5338d20c362974d4fe765a22
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "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] 1066ecd22e1357551d8a9cff976bbf5bcad3549659748b6be666b794920bde52
[INFO] running `Command { std: "docker" "start" "-a" "1066ecd22e1357551d8a9cff976bbf5bcad3549659748b6be666b794920bde52", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]    Compiling syn v1.0.48
[INFO] [stderr]    Compiling getrandom v0.1.15
[INFO] [stderr]    Compiling unicode-segmentation v1.7.0
[INFO] [stderr]    Compiling anyhow v1.0.34
[INFO] [stderr]    Compiling smallvec v1.4.2
[INFO] [stderr]    Compiling fixedbitset v0.2.0
[INFO] [stderr]    Compiling multimap v0.8.2
[INFO] [stderr]    Compiling match_cfg v0.1.0
[INFO] [stderr]    Compiling crc64 v1.0.0
[INFO] [stderr]    Compiling copyless v0.1.5
[INFO] [stderr]    Compiling serde v1.0.117
[INFO] [stderr]    Compiling regex-syntax v0.6.21
[INFO] [stderr]    Compiling humantime v2.0.1
[INFO] [stderr]    Compiling indexmap v1.6.0
[INFO] [stderr]    Compiling futures-channel v0.3.8
[INFO] [stderr]    Compiling itertools v0.8.2
[INFO] [stderr]    Compiling instant v0.1.8
[INFO] [stderr]    Compiling tinyvec v1.0.1
[INFO] [stderr]    Compiling lock_api v0.4.1
[INFO] [stderr]    Compiling addr2line v0.14.0
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling heck v0.3.1
[INFO] [stderr]    Compiling petgraph v0.5.1
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling net2 v0.2.35
[INFO] [stderr]    Compiling signal-hook-registry v1.2.2
[INFO] [stderr]    Compiling which v3.1.1
[INFO] [stderr]    Compiling parking_lot_core v0.8.0
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling backtrace v0.3.54
[INFO] [stderr]    Compiling hostname v0.3.1
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling unicode-normalization v0.1.14
[INFO] [stderr]    Compiling resolv-conf v0.7.0
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling threadpool v1.8.1
[INFO] [stderr]    Compiling parking_lot v0.11.0
[INFO] [stderr]    Compiling prost-build v0.6.1
[INFO] [stderr]    Compiling mio v0.6.22
[INFO] [stderr]    Compiling regex v1.4.2
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling idna v0.2.0
[INFO] [stderr]    Compiling mio-uds v0.6.8
[INFO] [stderr]    Compiling url v2.2.0
[INFO] [stderr]    Compiling env_logger v0.8.1
[INFO] [stderr]    Compiling tokio v0.2.23
[INFO] [stderr]    Compiling tempfile v3.1.0
[INFO] [stderr]    Compiling uuid v0.8.1
[INFO] [stderr]    Compiling tokio-util v0.3.1
[INFO] [stderr]    Compiling pin-project-internal v1.0.1
[INFO] [stderr]    Compiling futures-macro v0.3.8
[INFO] [stderr]    Compiling prost-derive v0.6.1
[INFO] [stderr]    Compiling thiserror-impl v1.0.22
[INFO] [stderr]    Compiling enum-as-inner v0.3.3
[INFO] [stderr]    Compiling async-trait v0.1.41
[INFO] [stderr]    Compiling pin-project-internal v0.4.27
[INFO] [stderr]    Compiling derive_more v0.99.11
[INFO] [stderr]    Compiling actix-macros v0.1.2
[INFO] [stderr]    Compiling actix_derive v0.5.0
[INFO] [stderr]    Compiling quix-derive v0.0.6
[INFO] [stderr]    Compiling thiserror v1.0.22
[INFO] [stderr]    Compiling pin-project v0.4.27
[INFO] [stderr]    Compiling actix-codec v0.3.0
[INFO] [stderr]    Compiling prost v0.6.1
[INFO] [stderr]    Compiling pin-project v1.0.1
[INFO] [stderr]    Compiling futures-util v0.3.8
[INFO] [stderr]    Compiling prost-types v0.6.1
[INFO] [stderr]    Compiling actix-threadpool v0.3.3
[INFO] [stderr]    Compiling quix-build v0.0.6
[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/quix-build-0.0.6/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(format_args_capture)]
[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 E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `quix-build`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "1066ecd22e1357551d8a9cff976bbf5bcad3549659748b6be666b794920bde52", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1066ecd22e1357551d8a9cff976bbf5bcad3549659748b6be666b794920bde52", kill_on_drop: false }`
[INFO] [stdout] 1066ecd22e1357551d8a9cff976bbf5bcad3549659748b6be666b794920bde52