[INFO] fetching crate brio 0.2.0...
[INFO] testing brio-0.2.0 against 1.49.0 for beta-1.50-1
[INFO] extracting crate brio 0.2.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate brio 0.2.0 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 brio 0.2.0
[INFO] finished tweaking crates.io crate brio 0.2.0
[INFO] tweaked toml for crates.io crate brio 0.2.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate brio 0.2.0 already has a lockfile, it will not be regenerated
[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-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 54de3f6afb9b7f2701a846c5d9abb8bd44c8c392c309ec166d60ae89be4df0fa
[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" "54de3f6afb9b7f2701a846c5d9abb8bd44c8c392c309ec166d60ae89be4df0fa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "54de3f6afb9b7f2701a846c5d9abb8bd44c8c392c309ec166d60ae89be4df0fa", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "54de3f6afb9b7f2701a846c5d9abb8bd44c8c392c309ec166d60ae89be4df0fa", kill_on_drop: false }`
[INFO] [stdout] 54de3f6afb9b7f2701a846c5d9abb8bd44c8c392c309ec166d60ae89be4df0fa
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] [stdout] fa26cecc56cc4f211578e980fe3ffa7d4380f61fd19512322f8b23cde98290e6
[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" "fa26cecc56cc4f211578e980fe3ffa7d4380f61fd19512322f8b23cde98290e6", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.14
[INFO] [stderr]    Compiling memchr v2.3.2
[INFO] [stderr]    Compiling log v0.4.8
[INFO] [stderr]    Compiling proc-macro-nested v0.1.3
[INFO] [stderr]    Compiling futures-core v0.3.4
[INFO] [stderr]    Compiling futures-io v0.3.4
[INFO] [stderr]    Compiling futures-sink v0.3.4
[INFO] [stderr]    Compiling futures-task v0.3.4
[INFO] [stderr]    Compiling serde v1.0.104
[INFO] [stderr]    Compiling arc-swap v0.4.4
[INFO] [stderr]    Compiling once_cell v1.3.1
[INFO] [stderr]    Compiling futures-timer v2.0.2
[INFO] [stderr]    Compiling futures-timer v3.0.2
[INFO] [stderr]    Compiling async-task v1.3.1
[INFO] [stderr]    Compiling memoffset v0.5.3
[INFO] [stderr]    Compiling futures-channel v0.3.4
[INFO] [stderr]    Compiling mime_guess v2.0.3
[INFO] [stderr]    Compiling signal-hook-registry v1.2.0
[INFO] [stderr]    Compiling signal-hook v0.1.13
[INFO] [stderr]    Compiling crossbeam-epoch v0.8.0
[INFO] [stderr]    Compiling mio v0.6.21
[INFO] [stderr]    Compiling kv-log-macro v1.0.4
[INFO] [stderr]    Compiling crossbeam-deque v0.7.2
[INFO] [stderr]    Compiling mio-uds v0.6.7
[INFO] [stderr]    Compiling async-std v1.5.0
[INFO] [stderr]    Compiling serde_json v1.0.48
[INFO] [stderr]    Compiling proc-macro-hack v0.5.11
[INFO] [stderr]    Compiling futures-macro v0.3.4
[INFO] [stderr]    Compiling futures-util v0.3.4
[INFO] [stderr]    Compiling futures-executor v0.3.4
[INFO] [stderr]    Compiling futures v0.3.4
[INFO] [stderr]    Compiling brio v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(async_closure)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(or_patterns)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(exclusive_range_pattern)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `brio`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "fa26cecc56cc4f211578e980fe3ffa7d4380f61fd19512322f8b23cde98290e6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fa26cecc56cc4f211578e980fe3ffa7d4380f61fd19512322f8b23cde98290e6", kill_on_drop: false }`
[INFO] [stdout] fa26cecc56cc4f211578e980fe3ffa7d4380f61fd19512322f8b23cde98290e6