[INFO] fetching crate lark-span 0.1.0...
[INFO] checking lark-span-0.1.0 against beta for pr-78714
[INFO] extracting crate lark-span 0.1.0 into /workspace/builds/worker-9/source
[INFO] validating manifest of crates.io crate lark-span 0.1.0 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 lark-span 0.1.0
[INFO] finished tweaking crates.io crate lark-span 0.1.0
[INFO] tweaked toml for crates.io crate lark-span 0.1.0 written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "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] 5bbb035bd349e4c339f8c1722a62daf3dab830445896c165d90867b130818487
[INFO] running `Command { std: "docker" "start" "-a" "5bbb035bd349e4c339f8c1722a62daf3dab830445896c165d90867b130818487", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5bbb035bd349e4c339f8c1722a62daf3dab830445896c165d90867b130818487", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5bbb035bd349e4c339f8c1722a62daf3dab830445896c165d90867b130818487", kill_on_drop: false }`
[INFO] [stdout] 5bbb035bd349e4c339f8c1722a62daf3dab830445896c165d90867b130818487
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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@sha256:6eabd152ff4036248d66efda456a36cb33d24b7291b33f25f75140726c88da35" "/opt/rustwide/cargo-home/bin/cargo" "+beta" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 479a4b110f2682b3d113d95721d7c1f84b207dea853bcbfe6bd888e5cb114934
[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" "479a4b110f2682b3d113d95721d7c1f84b207dea853bcbfe6bd888e5cb114934", kill_on_drop: false }`
[INFO] [stderr]     Checking lock_api v0.1.5
[INFO] [stderr]    Compiling num-derive v0.2.5
[INFO] [stderr]     Checking url v1.7.2
[INFO] [stderr]     Checking render-tree v0.1.1
[INFO] [stderr]     Checking lark-debug-with v0.1.0
[INFO] [stderr]     Checking rand v0.6.5
[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/lark-debug-with-0.1.0/src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(box_patterns)]
[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/lark-debug-with-0.1.0/src/lib.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(never_type)]
[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/lark-debug-with-0.1.0/src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![feature(in_band_lifetimes)]
[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/lark-debug-with-0.1.0/src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(specialization)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lark-debug-with`
[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" "479a4b110f2682b3d113d95721d7c1f84b207dea853bcbfe6bd888e5cb114934", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "479a4b110f2682b3d113d95721d7c1f84b207dea853bcbfe6bd888e5cb114934", kill_on_drop: false }`
[INFO] [stdout] 479a4b110f2682b3d113d95721d7c1f84b207dea853bcbfe6bd888e5cb114934