[INFO] fetching crate hexchat 0.6.3...
[INFO] testing hexchat-0.6.3 against 1.49.0 for beta-1.50-1
[INFO] extracting crate hexchat 0.6.3 into /workspace/builds/worker-6/source
[INFO] validating manifest of crates.io crate hexchat 0.6.3 on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate hexchat 0.6.3
[INFO] finished tweaking crates.io crate hexchat 0.6.3
[INFO] tweaked toml for crates.io crate hexchat 0.6.3 written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "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" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0add605b54899b16358ffb4a2e1fd15a846d2c5e75c40c27720bf4fb6130609a
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "0add605b54899b16358ffb4a2e1fd15a846d2c5e75c40c27720bf4fb6130609a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0add605b54899b16358ffb4a2e1fd15a846d2c5e75c40c27720bf4fb6130609a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0add605b54899b16358ffb4a2e1fd15a846d2c5e75c40c27720bf4fb6130609a", kill_on_drop: false }`
[INFO] [stdout] 0add605b54899b16358ffb4a2e1fd15a846d2c5e75c40c27720bf4fb6130609a
[INFO] running `Command { std: "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" "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" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 17f7acbe3c79cfa650375bd9b463d4a15b0c8c9116e95ba39cf54b91477d089d
[INFO] running `Command { std: "docker" "start" "-a" "17f7acbe3c79cfa650375bd9b463d4a15b0c8c9116e95ba39cf54b91477d089d", kill_on_drop: false }`
[INFO] [stderr]    Compiling charsets v0.2.0
[INFO] [stderr]    Compiling lock_api v0.1.5
[INFO] [stderr]    Compiling parking_lot_core v0.4.0
[INFO] [stderr]    Compiling phf_macros v0.7.24
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/lock_api-0.1.5/src/lib.rs:88:34
[INFO] [stdout]    |
[INFO] [stdout] 88 | #![cfg_attr(feature = "nightly", feature(const_fn))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lock_api`
[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 `Command { std: "docker" "inspect" "17f7acbe3c79cfa650375bd9b463d4a15b0c8c9116e95ba39cf54b91477d089d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "17f7acbe3c79cfa650375bd9b463d4a15b0c8c9116e95ba39cf54b91477d089d", kill_on_drop: false }`
[INFO] [stdout] 17f7acbe3c79cfa650375bd9b463d4a15b0c8c9116e95ba39cf54b91477d089d