[INFO] fetching crate lain 0.4.1...
[INFO] testing lain-0.4.1 against beta-2020-06-03 for beta-1.45-1
[INFO] extracting crate lain 0.4.1 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate lain 0.4.1 on toolchain beta-2020-06-03
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate lain 0.4.1
[INFO] finished tweaking crates.io crate lain 0.4.1
[INFO] tweaked toml for crates.io crate lain 0.4.1 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded field-offset v0.3.1
[INFO] [stderr]   Downloaded lain_derive v0.4.1
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "+beta-2020-06-03" "build" "--frozen"`
[INFO] [stdout] 0031efeb0d48e12a70dfa66cd8c18674f039efc1b7abe30dc7eb3be21b853f8e
[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" "0031efeb0d48e12a70dfa66cd8c18674f039efc1b7abe30dc7eb3be21b853f8e"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling libc v0.2.71
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling ppv-lite86 v0.2.8
[INFO] [stderr]    Compiling num-derive v0.2.5
[INFO] [stderr]    Compiling num-traits v0.2.11
[INFO] [stderr]    Compiling num-integer v0.1.42
[INFO] [stderr]    Compiling num-bigint v0.2.6
[INFO] [stderr]    Compiling num-iter v0.1.40
[INFO] [stderr]    Compiling num-rational v0.2.4
[INFO] [stderr]    Compiling num-complex v0.2.4
[INFO] [stderr]    Compiling field-offset v0.3.1
[INFO] [stderr]    Compiling lain_derive v0.4.1
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling rand_pcg v0.2.1
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling num v0.2.1
[INFO] [stderr]    Compiling lain v0.4.1 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]    --> src/lib.rs:101:1
[INFO] [stderr]     |
[INFO] [stderr] 101 | #![feature(specialization)]
[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 `lain`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0031efeb0d48e12a70dfa66cd8c18674f039efc1b7abe30dc7eb3be21b853f8e"`
[INFO] running `"docker" "rm" "-f" "0031efeb0d48e12a70dfa66cd8c18674f039efc1b7abe30dc7eb3be21b853f8e"`
[INFO] [stdout] 0031efeb0d48e12a70dfa66cd8c18674f039efc1b7abe30dc7eb3be21b853f8e