[INFO] fetching crate overloadable 0.4.1...
[INFO] testing overloadable-0.4.1 against 1.49.0 for beta-1.50-1
[INFO] extracting crate overloadable 0.4.1 into /workspace/builds/worker-11/source
[INFO] validating manifest of crates.io crate overloadable 0.4.1 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 overloadable 0.4.1
[INFO] finished tweaking crates.io crate overloadable 0.4.1
[INFO] tweaked toml for crates.io crate overloadable 0.4.1 written to /workspace/builds/worker-11/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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] 4bc262ad0477d18bc7f047634dcb8941ea3580024f7ff33ad68f6a05715c992b
[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" "4bc262ad0477d18bc7f047634dcb8941ea3580024f7ff33ad68f6a05715c992b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4bc262ad0477d18bc7f047634dcb8941ea3580024f7ff33ad68f6a05715c992b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4bc262ad0477d18bc7f047634dcb8941ea3580024f7ff33ad68f6a05715c992b", kill_on_drop: false }`
[INFO] [stdout] 4bc262ad0477d18bc7f047634dcb8941ea3580024f7ff33ad68f6a05715c992b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] 8ea57656d5dd9c12e8a927b90c80a24d3d2228e7541ab16e59c2908b9521d687
[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" "8ea57656d5dd9c12e8a927b90c80a24d3d2228e7541ab16e59c2908b9521d687", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling overloadable v0.4.1 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 16.33s
[INFO] running `Command { std: "docker" "inspect" "8ea57656d5dd9c12e8a927b90c80a24d3d2228e7541ab16e59c2908b9521d687", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8ea57656d5dd9c12e8a927b90c80a24d3d2228e7541ab16e59c2908b9521d687", kill_on_drop: false }`
[INFO] [stdout] 8ea57656d5dd9c12e8a927b90c80a24d3d2228e7541ab16e59c2908b9521d687
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-11/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] ba20c54d02cc76d15ab9b8fe20b980651a670a17c32ae8a936f83ea11055b222
[INFO] running `Command { std: "docker" "start" "-a" "ba20c54d02cc76d15ab9b8fe20b980651a670a17c32ae8a936f83ea11055b222", kill_on_drop: false }`
[INFO] [stderr]    Compiling overloadable v0.4.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> tests/default.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(unboxed_closures, fn_traits)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary braces around block return value
[INFO] [stdout]   --> tests/default.rs:38:24
[INFO] [stdout]    |
[INFO] [stdout] 38 |     fn(&self) -> usize {1}
[INFO] [stdout]    |                        ^^^ help: remove these braces
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_braces)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `overloadable`
[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" "ba20c54d02cc76d15ab9b8fe20b980651a670a17c32ae8a936f83ea11055b222", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ba20c54d02cc76d15ab9b8fe20b980651a670a17c32ae8a936f83ea11055b222", kill_on_drop: false }`
[INFO] [stdout] ba20c54d02cc76d15ab9b8fe20b980651a670a17c32ae8a936f83ea11055b222