[INFO] fetching crate yolk 0.6.0...
[INFO] checking yolk-0.6.0 against beta for pr-78714
[INFO] extracting crate yolk 0.6.0 into /workspace/builds/worker-8/source
[INFO] validating manifest of crates.io crate yolk 0.6.0 on toolchain beta
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate yolk 0.6.0
[INFO] finished tweaking crates.io crate yolk 0.6.0
[INFO] tweaked toml for crates.io crate yolk 0.6.0 written to /workspace/builds/worker-8/source/Cargo.toml
[INFO] crate crates.io crate yolk 0.6.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "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-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 05465b12dcf0e93d62220bff760ae53be15a4ef21c1cd723dc0c462721bc20b3
[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" "05465b12dcf0e93d62220bff760ae53be15a4ef21c1cd723dc0c462721bc20b3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "05465b12dcf0e93d62220bff760ae53be15a4ef21c1cd723dc0c462721bc20b3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "05465b12dcf0e93d62220bff760ae53be15a4ef21c1cd723dc0c462721bc20b3", kill_on_drop: false }`
[INFO] [stdout] 05465b12dcf0e93d62220bff760ae53be15a4ef21c1cd723dc0c462721bc20b3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-8/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=forbid" "-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:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 608d3ea350e746eb765908c71b09bc775fa9773f96cbd600fc15b1b4134cc1a2
[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" "608d3ea350e746eb765908c71b09bc775fa9773f96cbd600fc15b1b4134cc1a2", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.2
[INFO] [stderr]    Compiling syn v1.0.5
[INFO] [stderr]    Compiling libc v0.2.62
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling serde v1.0.99
[INFO] [stderr]    Compiling cc v1.0.41
[INFO] [stderr]     Checking regex-syntax v0.6.11
[INFO] [stderr]    Compiling bitflags v1.1.0
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]     Checking cfg-if v0.1.9
[INFO] [stderr]    Compiling pest v2.1.1
[INFO] [stderr]    Compiling quote v1.0.2
[INFO] [stderr]     Checking atty v0.2.13
[INFO] [stderr]     Checking clap v2.33.0
[INFO] [stderr]    Compiling backtrace-sys v0.1.31
[INFO] [stderr]     Checking regex v1.2.1
[INFO] [stderr]    Compiling pest_meta v2.1.1
[INFO] [stderr]     Checking backtrace v0.3.35
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling pest_generator v2.1.0
[INFO] [stderr]    Compiling pest_derive v2.1.0
[INFO] [stderr]     Checking failure v0.1.5
[INFO] [stderr]    Compiling serde_derive v1.0.99
[INFO] [stderr]     Checking serde_json v1.0.40
[INFO] [stderr]     Checking yolol_number v0.7.0
[INFO] [stderr]     Checking yolol_number v0.6.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/yolol_number-0.7.0/src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(trait_alias)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/yolol_number-0.6.2/src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(trait_alias)]
[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 `yolol_number`
[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] [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: build failed
[INFO] running `Command { std: "docker" "inspect" "608d3ea350e746eb765908c71b09bc775fa9773f96cbd600fc15b1b4134cc1a2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "608d3ea350e746eb765908c71b09bc775fa9773f96cbd600fc15b1b4134cc1a2", kill_on_drop: false }`
[INFO] [stdout] 608d3ea350e746eb765908c71b09bc775fa9773f96cbd600fc15b1b4134cc1a2