[INFO] updating cached repository https://github.com/ZiCog/loop_blocking
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] e63453367df7a2ceeff3396170f16082fb3fea32
[INFO] testing ZiCog/loop_blocking against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FZiCog%2Floop_blocking" "/workspace/builds/worker-8/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-8/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ZiCog/loop_blocking on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/ZiCog/loop_blocking
[INFO] finished tweaking git repo https://github.com/ZiCog/loop_blocking
[INFO] tweaked toml for git repo https://github.com/ZiCog/loop_blocking written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/ZiCog/loop_blocking 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] d2f82e6a3bcf3cf08c798fc7d46a6b746b34d801b1e74f90d9a80e08b5354545
[INFO] running `"docker" "start" "-a" "d2f82e6a3bcf3cf08c798fc7d46a6b746b34d801b1e74f90d9a80e08b5354545"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling time v0.2.1
[INFO] [stderr]    Compiling unchecked-index v0.2.2
[INFO] [stderr]    Compiling loop_blocking v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:6:1
[INFO] [stderr]   |
[INFO] [stderr] 6 | #![feature(register_tool)]
[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 `loop_blocking`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "d2f82e6a3bcf3cf08c798fc7d46a6b746b34d801b1e74f90d9a80e08b5354545"`
[INFO] running `"docker" "rm" "-f" "d2f82e6a3bcf3cf08c798fc7d46a6b746b34d801b1e74f90d9a80e08b5354545"`
[INFO] [stdout] d2f82e6a3bcf3cf08c798fc7d46a6b746b34d801b1e74f90d9a80e08b5354545