[INFO] updating cached repository https://github.com/fun4wut/naive-concurrent
[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] f05a13d9e9e20947d08b65a6adcc6d21b327c850
[INFO] testing fun4wut/naive-concurrent against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ffun4wut%2Fnaive-concurrent" "/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/fun4wut/naive-concurrent 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/fun4wut/naive-concurrent
[INFO] finished tweaking git repo https://github.com/fun4wut/naive-concurrent
[INFO] tweaked toml for git repo https://github.com/fun4wut/naive-concurrent written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate git repo https://github.com/fun4wut/naive-concurrent 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] 30f528464a7e8c170c3225dc0582b6fe084bacd3f50c430a6f9100be2fafb34e
[INFO] running `"docker" "start" "-a" "30f528464a7e8c170c3225dc0582b6fe084bacd3f50c430a6f9100be2fafb34e"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling arrayvec v0.4.12
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling nodrop v0.1.14
[INFO] [stderr]    Compiling smallvec v0.6.10
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling lock_api v0.3.1
[INFO] [stderr]    Compiling memoffset v0.5.1
[INFO] [stderr]    Compiling parking_lot_core v0.6.2
[INFO] [stderr]    Compiling parking_lot v0.9.0
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling iovec v0.1.4
[INFO] [stderr]    Compiling net2 v0.2.33
[INFO] [stderr]    Compiling num_cpus v1.10.1
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling async-macros v1.0.0
[INFO] [stderr]    Compiling crossbeam-channel v0.3.9
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling async-task v1.0.0
[INFO] [stderr]    Compiling mio v0.6.19
[INFO] [stderr]    Compiling kv-log-macro v1.0.4
[INFO] [stderr]    Compiling crossbeam-epoch v0.7.2
[INFO] [stderr]    Compiling scheduled-thread-pool v0.2.2
[INFO] [stderr]    Compiling crossbeam-deque v0.7.1
[INFO] [stderr]    Compiling crossbeam v0.7.2
[INFO] [stderr]    Compiling mio-uds v0.6.7
[INFO] [stderr]    Compiling broadcaster v0.2.6
[INFO] [stderr]    Compiling futures-timer v1.0.2
[INFO] [stderr]    Compiling async-std v0.99.10
[INFO] [stderr]    Compiling webserver 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:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(box_syntax)]
[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 `webserver`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "30f528464a7e8c170c3225dc0582b6fe084bacd3f50c430a6f9100be2fafb34e"`
[INFO] running `"docker" "rm" "-f" "30f528464a7e8c170c3225dc0582b6fe084bacd3f50c430a6f9100be2fafb34e"`
[INFO] [stdout] 30f528464a7e8c170c3225dc0582b6fe084bacd3f50c430a6f9100be2fafb34e