[INFO] cloning repository https://github.com/Centril/rust_strong_rc
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Centril/rust_strong_rc" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCentril%2Frust_strong_rc"`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCentril%2Frust_strong_rc'...
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 67190f782090bd5aa95bbedb40d1ac292e08cd10
[INFO] testing Centril/rust_strong_rc against beta-2020-06-03 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCentril%2Frust_strong_rc" "/workspace/builds/worker-0/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Centril/rust_strong_rc 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 git repo https://github.com/Centril/rust_strong_rc
[INFO] finished tweaking git repo https://github.com/Centril/rust_strong_rc
[INFO] tweaked toml for git repo https://github.com/Centril/rust_strong_rc written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/Centril/rust_strong_rc already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+beta-2020-06-03" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] df321f151642d994b67cccf36937917cf0de238fd3731532dcc67c9c48837bd2
[INFO] running `"docker" "start" "-a" "df321f151642d994b67cccf36937917cf0de238fd3731532dcc67c9c48837bd2"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling strong_rc v0.1.4 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]    --> src/lib.rs:120:1
[INFO] [stderr]     |
[INFO] [stderr] 120 | #![feature(unsize, coerce_unsized)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]    --> src/lib.rs:121:1
[INFO] [stderr]     |
[INFO] [stderr] 121 | #![feature(specialization)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]    --> src/lib.rs:122:1
[INFO] [stderr]     |
[INFO] [stderr] 122 | #![feature(allocator_api)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stderr]    --> src/lib.rs:123:1
[INFO] [stderr]     |
[INFO] [stderr] 123 | #![feature(alloc_layout_extra)]
[INFO] [stderr]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `strong_rc`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "df321f151642d994b67cccf36937917cf0de238fd3731532dcc67c9c48837bd2"`
[INFO] running `"docker" "rm" "-f" "df321f151642d994b67cccf36937917cf0de238fd3731532dcc67c9c48837bd2"`
[INFO] [stdout] df321f151642d994b67cccf36937917cf0de238fd3731532dcc67c9c48837bd2