[INFO] fetching crate muta-protocol 0.1.0-alpha.1...
[INFO] testing muta-protocol-0.1.0-alpha.1 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate muta-protocol 0.1.0-alpha.1 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate muta-protocol 0.1.0-alpha.1 on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate muta-protocol 0.1.0-alpha.1
[INFO] finished tweaking crates.io crate muta-protocol 0.1.0-alpha.1
[INFO] tweaked toml for crates.io crate muta-protocol 0.1.0-alpha.1 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded rustc-hex v2.1.0
[INFO] [stderr]   Downloaded fixed-hash v0.5.2
[INFO] [stderr]   Downloaded prost-derive v0.6.1
[INFO] [stderr]   Downloaded ethereum-types v0.4.2
[INFO] [stderr]   Downloaded uint v0.4.1
[INFO] [stderr]   Downloaded heapsize v0.4.2
[INFO] [stderr]   Downloaded lock_api v0.2.0
[INFO] [stderr]   Downloaded parking_lot_core v0.5.0
[INFO] [stderr]   Downloaded hashbrown v0.3.1
[INFO] [stderr]   Downloaded rlp v0.4.6
[INFO] [stderr]   Downloaded parking_lot v0.8.0
[INFO] [stderr]   Downloaded ethbloom v0.5.3
[INFO] [stderr]   Downloaded ethereum-types-serialize v0.2.2
[INFO] [stderr]   Downloaded fixed-hash v0.2.5
[INFO] [stderr]   Downloaded crunchy v0.1.6
[INFO] [stderr]   Downloaded hasher v0.1.3
[INFO] [stderr]   Downloaded rlp v0.3.0
[INFO] [stderr]   Downloaded cita_trie v2.0.0
[INFO] [stderr]   Downloaded impl-rlp v0.2.1
[INFO] [stderr]   Downloaded impl-serde v0.2.3
[INFO] [stderr]   Downloaded prost v0.6.1
[INFO] [stderr]   Downloaded ethbloom v0.8.1
[INFO] [stderr]   Downloaded json v0.12.4
[INFO] [stderr]   Downloaded creep v0.1.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", 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] ab3b701b5e52fba09e220a43f294f1f761b3b731b076ee35b64dd4d2c4ec132a
[INFO] running `Command { std: "docker" "start" "-a" "ab3b701b5e52fba09e220a43f294f1f761b3b731b076ee35b64dd4d2c4ec132a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ab3b701b5e52fba09e220a43f294f1f761b3b731b076ee35b64dd4d2c4ec132a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ab3b701b5e52fba09e220a43f294f1f761b3b731b076ee35b64dd4d2c4ec132a", kill_on_drop: false }`
[INFO] [stdout] ab3b701b5e52fba09e220a43f294f1f761b3b731b076ee35b64dd4d2c4ec132a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "+beta-2021-01-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f899504fff39f45e252a265b0ba1b400645c9f486ad2de6c7802d891385dec51
[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" "f899504fff39f45e252a265b0ba1b400645c9f486ad2de6c7802d891385dec51", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling heapsize v0.4.2
[INFO] [stderr]    Compiling crunchy v0.1.6
[INFO] [stderr]    Compiling hashbrown v0.3.1
[INFO] [stderr]    Compiling creep v0.1.1
[INFO] [stderr]    Compiling lock_api v0.2.0
[INFO] [stderr]    Compiling parking_lot_core v0.5.0
[INFO] [stderr]    Compiling parking_lot v0.8.0
[INFO] [stderr]    Compiling hasher v0.1.3
[INFO] [stderr]    Compiling prost-derive v0.6.1
[INFO] [stderr]    Compiling ethereum-types-serialize v0.2.2
[INFO] [stderr]    Compiling impl-serde v0.2.3
[INFO] [stderr]    Compiling fixed-hash v0.5.2
[INFO] [stderr]    Compiling derive_more v0.15.0
[INFO] [stderr]    Compiling ethbloom v0.8.1
[INFO] [stderr]    Compiling fixed-hash v0.2.5
[INFO] [stderr]    Compiling uint v0.4.1
[INFO] [stderr]    Compiling ethbloom v0.5.3
[INFO] [stderr]    Compiling ethereum-types v0.4.2
[INFO] [stderr]    Compiling prost v0.6.1
[INFO] [stderr]    Compiling rlp v0.3.0
[INFO] [stderr]    Compiling cita_trie v2.0.0
[INFO] [stderr]    Compiling muta-protocol v0.1.0-alpha.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(test)]
[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 `muta-protocol`
[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" "f899504fff39f45e252a265b0ba1b400645c9f486ad2de6c7802d891385dec51", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f899504fff39f45e252a265b0ba1b400645c9f486ad2de6c7802d891385dec51", kill_on_drop: false }`
[INFO] [stdout] f899504fff39f45e252a265b0ba1b400645c9f486ad2de6c7802d891385dec51