[INFO] crate bottle 1.1.0-alpha is already in cache
[INFO] testing bottle-1.1.0-alpha against 1.44.0 for beta-1.45-1
[INFO] extracting crate bottle 1.1.0-alpha into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate bottle 1.1.0-alpha on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate bottle 1.1.0-alpha
[INFO] finished tweaking crates.io crate bottle 1.1.0-alpha
[INFO] tweaked toml for crates.io crate bottle 1.1.0-alpha written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate crates.io crate bottle 1.1.0-alpha already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] d164d6bc18e9aa9755a9656f631ca00a0df7d1396a14232d8c58fb0c3681a34d
[INFO] running `"docker" "start" "-a" "d164d6bc18e9aa9755a9656f631ca00a0df7d1396a14232d8c58fb0c3681a34d"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v1.0.17
[INFO] [stderr]    Compiling proc-macro-nested v0.1.4
[INFO] [stderr]    Compiling libc v0.2.68
[INFO] [stderr]    Compiling futures-sink v0.3.4
[INFO] [stderr]    Compiling futures-task v0.3.4
[INFO] [stderr]    Compiling smallvec v1.3.0
[INFO] [stderr]    Compiling static_assertions v1.1.0
[INFO] [stderr]    Compiling futures-channel v0.3.4
[INFO] [stderr]    Compiling parking_lot_core v0.7.1
[INFO] [stderr]    Compiling parking_lot v0.10.2
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]    Compiling futures-util v0.3.4
[INFO] [stderr]    Compiling futures-executor v0.3.4
[INFO] [stderr]    Compiling futures v0.3.4
[INFO] [stderr]    Compiling bottle v1.1.0-alpha (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> src/lib.rs:1:1
[INFO] [stderr]    |
[INFO] [stderr] 1  | / #![feature(
[INFO] [stderr] 2  | |     // To allow the use of `Receiver<Self>` as `self` type.
[INFO] [stderr] 3  | |     arbitrary_self_types,
[INFO] [stderr] 4  | |
[INFO] [stderr] ...  |
[INFO] [stderr] 20 | |     weak_into_raw
[INFO] [stderr] 21 | | )]
[INFO] [stderr]    | |__^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `bottle`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "d164d6bc18e9aa9755a9656f631ca00a0df7d1396a14232d8c58fb0c3681a34d"`
[INFO] running `"docker" "rm" "-f" "d164d6bc18e9aa9755a9656f631ca00a0df7d1396a14232d8c58fb0c3681a34d"`
[INFO] [stdout] d164d6bc18e9aa9755a9656f631ca00a0df7d1396a14232d8c58fb0c3681a34d