[INFO] fetching crate muta-apm 0.1.0-alpha.15...
[INFO] testing muta-apm-0.1.0-alpha.15 against 1.49.0 for beta-1.50-1
[INFO] extracting crate muta-apm 0.1.0-alpha.15 into /workspace/builds/worker-10/source
[INFO] validating manifest of crates.io crate muta-apm 0.1.0-alpha.15 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 muta-apm 0.1.0-alpha.15
[INFO] finished tweaking crates.io crate muta-apm 0.1.0-alpha.15
[INFO] tweaked toml for crates.io crate muta-apm 0.1.0-alpha.15 written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate crates.io crate muta-apm 0.1.0-alpha.15 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-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 5d565559c55be3fff2bdfd5498b2bedbe2d447f7ce81dcd582d46d484d07fa99
[INFO] running `Command { std: "docker" "start" "-a" "5d565559c55be3fff2bdfd5498b2bedbe2d447f7ce81dcd582d46d484d07fa99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5d565559c55be3fff2bdfd5498b2bedbe2d447f7ce81dcd582d46d484d07fa99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5d565559c55be3fff2bdfd5498b2bedbe2d447f7ce81dcd582d46d484d07fa99", kill_on_drop: false }`
[INFO] [stdout] 5d565559c55be3fff2bdfd5498b2bedbe2d447f7ce81dcd582d46d484d07fa99
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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] b93cde0ef03b3a6c5c66b74913acd1122bb873cbc5eda1c8e406571822972f0a
[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" "b93cde0ef03b3a6c5c66b74913acd1122bb873cbc5eda1c8e406571822972f0a", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.21
[INFO] [stderr]    Compiling serde v1.0.110
[INFO] [stderr]    Compiling dyn-clone v1.0.1
[INFO] [stderr]    Compiling addr2line v0.12.0
[INFO] [stderr]    Compiling getrandom v0.1.14
[INFO] [stderr]    Compiling hostname v0.3.1
[INFO] [stderr]    Compiling parking_lot_core v0.7.2
[INFO] [stderr]    Compiling creep v0.2.2
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling parking_lot v0.10.2
[INFO] [stderr]    Compiling backtrace v0.3.47
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling trackable_derive v0.1.3
[INFO] [stderr]    Compiling serde_derive v1.0.110
[INFO] [stderr]    Compiling trackable v0.2.23
[INFO] [stderr]    Compiling rustracing v0.4.0
[INFO] [stderr]    Compiling thrift_codec v0.1.1
[INFO] [stderr]    Compiling rustracing_jaeger v0.4.1
[INFO] [stderr]    Compiling serde_json v1.0.53
[INFO] [stderr]    Compiling muta-apm-derive v0.1.0-alpha.12
[INFO] [stderr]    Compiling muta-apm v0.1.0-alpha.15 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 59.43s
[INFO] running `Command { std: "docker" "inspect" "b93cde0ef03b3a6c5c66b74913acd1122bb873cbc5eda1c8e406571822972f0a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b93cde0ef03b3a6c5c66b74913acd1122bb873cbc5eda1c8e406571822972f0a", kill_on_drop: false }`
[INFO] [stdout] b93cde0ef03b3a6c5c66b74913acd1122bb873cbc5eda1c8e406571822972f0a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 4242b1dc73204a34714a87a7aea70f5e6713172c169fb11f4541964c4c8a5741
[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" "4242b1dc73204a34714a87a7aea70f5e6713172c169fb11f4541964c4c8a5741", 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 proc-macro-nested v0.1.4
[INFO] [stderr]    Compiling proc-macro-hack v0.5.15
[INFO] [stderr]    Compiling pin-project-lite v0.1.5
[INFO] [stderr]    Compiling bit-vec v0.6.2
[INFO] [stderr]    Compiling rustc-hex v2.1.0
[INFO] [stderr]    Compiling futures-task v0.3.5
[INFO] [stderr]    Compiling futures-channel v0.3.5
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling pin-project-internal v0.4.16
[INFO] [stderr]    Compiling tokio-macros v0.2.5
[INFO] [stderr]    Compiling libmath v0.1.4
[INFO] [stderr]    Compiling async-trait v0.1.31
[INFO] [stderr]    Compiling rand_pcg v0.2.1
[INFO] [stderr]    Compiling derive_more v0.99.5
[INFO] [stderr]    Compiling bytes v0.5.4
[INFO] [stderr]    Compiling moodyblues-sdk v0.3.0
[INFO] [stderr]    Compiling prime_tools v0.2.2
[INFO] [stderr]    Compiling rlp v0.4.5
[INFO] [stderr]    Compiling futures-macro v0.3.5
[INFO] [stderr]    Compiling tokio v0.2.20
[INFO] [stderr]    Compiling pin-project v0.4.16
[INFO] [stderr]    Compiling futures-util v0.3.5
[INFO] [stderr]    Compiling futures-executor v0.3.5
[INFO] [stderr]    Compiling futures v0.3.5
[INFO] [stderr]    Compiling overlord v0.2.0-alpha.13
[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/overlord-0.2.0-alpha.13/src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![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 `overlord`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "4242b1dc73204a34714a87a7aea70f5e6713172c169fb11f4541964c4c8a5741", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4242b1dc73204a34714a87a7aea70f5e6713172c169fb11f4541964c4c8a5741", kill_on_drop: false }`
[INFO] [stdout] 4242b1dc73204a34714a87a7aea70f5e6713172c169fb11f4541964c4c8a5741