[INFO] fetching crate bve 0.0.1...
[INFO] testing bve-0.0.1 against 1.49.0 for beta-1.50-1
[INFO] extracting crate bve 0.0.1 into /workspace/builds/worker-3/source
[INFO] validating manifest of crates.io crate bve 0.0.1 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 bve 0.0.1
[INFO] finished tweaking crates.io crate bve 0.0.1
[INFO] tweaked toml for crates.io crate bve 0.0.1 written to /workspace/builds/worker-3/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-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] 1b5f8bd3cdb3ae557820e16b182a5bff0b5e136ca6be1f02269fda0d3e8cb352
[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" "1b5f8bd3cdb3ae557820e16b182a5bff0b5e136ca6be1f02269fda0d3e8cb352", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1b5f8bd3cdb3ae557820e16b182a5bff0b5e136ca6be1f02269fda0d3e8cb352", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1b5f8bd3cdb3ae557820e16b182a5bff0b5e136ca6be1f02269fda0d3e8cb352", kill_on_drop: false }`
[INFO] [stdout] 1b5f8bd3cdb3ae557820e16b182a5bff0b5e136ca6be1f02269fda0d3e8cb352
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3/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] 656a45811ff50505f7b9834e0c03a7f5bbea1510012f0520b3dc4eb10302e150
[INFO] running `Command { std: "docker" "start" "-a" "656a45811ff50505f7b9834e0c03a7f5bbea1510012f0520b3dc4eb10302e150", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.57
[INFO] [stderr]    Compiling tinystr v0.3.4
[INFO] [stderr]    Compiling cgmath v0.17.0
[INFO] [stderr]    Compiling fluent-syntax v0.9.3
[INFO] [stderr]    Compiling regex-automata v0.1.9
[INFO] [stderr]    Compiling type-map v0.3.0
[INFO] [stderr]    Compiling chardetng v0.1.10
[INFO] [stderr]    Compiling approx v0.3.2
[INFO] [stderr]    Compiling locale_config v0.3.0
[INFO] [stderr]    Compiling unic-langid-impl v0.8.0
[INFO] [stderr]    Compiling unic-locale-impl v0.8.0
[INFO] [stderr]    Compiling unic-locale v0.8.0
[INFO] [stderr]    Compiling synstructure v0.12.4
[INFO] [stderr]    Compiling darling_core v0.10.2
[INFO] [stderr]    Compiling serde_derive v1.0.118
[INFO] [stderr]    Compiling unic-langid-macros-impl v0.8.0
[INFO] [stderr]    Compiling failure_derive v0.1.8
[INFO] [stderr]    Compiling rental-impl v0.5.5
[INFO] [stderr]    Compiling tracing-attributes v0.1.11
[INFO] [stderr]    Compiling darling_macro v0.10.2
[INFO] [stderr]    Compiling unic-langid-macros v0.8.0
[INFO] [stderr]    Compiling failure v0.1.8
[INFO] [stderr]    Compiling unic-langid v0.8.0
[INFO] [stderr]    Compiling fluent-langneg v0.12.1
[INFO] [stderr]    Compiling intl_pluralrules v6.0.0
[INFO] [stderr]    Compiling intl-memoizer v0.3.0
[INFO] [stderr]    Compiling darling v0.10.2
[INFO] [stderr]    Compiling include_dir_impl v0.5.0
[INFO] [stderr]    Compiling bve-derive v0.0.1
[INFO] [stderr]    Compiling tracing v0.1.22
[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/bve-derive-0.0.1/src/lib.rs:50:1
[INFO] [stdout]    |
[INFO] [stdout] 50 | #![feature(core_panic)]
[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 `bve-derive`
[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" "656a45811ff50505f7b9834e0c03a7f5bbea1510012f0520b3dc4eb10302e150", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "656a45811ff50505f7b9834e0c03a7f5bbea1510012f0520b3dc4eb10302e150", kill_on_drop: false }`
[INFO] [stdout] 656a45811ff50505f7b9834e0c03a7f5bbea1510012f0520b3dc4eb10302e150