[INFO] crate mason 0.0.0 is already in cache
[INFO] testing mason-0.0.0 against 1.44.0 for beta-1.45-1
[INFO] extracting crate mason 0.0.0 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate mason 0.0.0 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 mason 0.0.0
[INFO] finished tweaking crates.io crate mason 0.0.0
[INFO] tweaked toml for crates.io crate mason 0.0.0 written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[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-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" "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] [stdout] 9d933d4d4e8798bee297ee7d1aabdabb6d1ad91520e16b60f0dbc3333914a05e
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `"docker" "start" "-a" "9d933d4d4e8798bee297ee7d1aabdabb6d1ad91520e16b60f0dbc3333914a05e"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling proc-macro2 v1.0.18
[INFO] [stderr]    Compiling async-ready v3.0.0
[INFO] [stderr]    Compiling async-datagram v3.0.0
[INFO] [stderr]    Compiling futures-timer v0.3.0
[INFO] [stderr]    Compiling runtime-raw v0.3.0-alpha.5
[INFO] [stderr]    Compiling juliex v0.3.0-alpha.8
[INFO] [stderr]    Compiling romio v0.3.0-alpha.10
[INFO] [stderr]    Compiling runtime-native v0.3.0-alpha.6
[INFO] [stderr]    Compiling quote v1.0.6
[INFO] [stderr]    Compiling syn v1.0.30
[INFO] [stderr]    Compiling synstructure v0.12.3
[INFO] [stderr]    Compiling runtime-attributes v0.3.0-alpha.6
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling runtime v0.3.0-alpha.4
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/runtime-0.3.0-alpha.4/src/lib.rs:88:1
[INFO] [stderr]    |
[INFO] [stderr] 88 | #![feature(async_await)]
[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]    Compiling failure v0.1.8
[INFO] [stderr] error: could not compile `runtime`.
[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 `"docker" "inspect" "9d933d4d4e8798bee297ee7d1aabdabb6d1ad91520e16b60f0dbc3333914a05e"`
[INFO] running `"docker" "rm" "-f" "9d933d4d4e8798bee297ee7d1aabdabb6d1ad91520e16b60f0dbc3333914a05e"`
[INFO] [stdout] 9d933d4d4e8798bee297ee7d1aabdabb6d1ad91520e16b60f0dbc3333914a05e