[INFO] fetching crate libass 0.1.3...
[INFO] checking libass-0.1.3 against beta for pr-78714
[INFO] extracting crate libass 0.1.3 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate libass 0.1.3 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 libass 0.1.3
[INFO] finished tweaking crates.io crate libass 0.1.3
[INFO] tweaked toml for crates.io crate libass 0.1.3 written to /workspace/builds/worker-0/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-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stdout] 439a888831ff7b2c1f4e59af8bb4a30290e823cc77491b933cbc6ea5d1f7d0ef
[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" "439a888831ff7b2c1f4e59af8bb4a30290e823cc77491b933cbc6ea5d1f7d0ef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "439a888831ff7b2c1f4e59af8bb4a30290e823cc77491b933cbc6ea5d1f7d0ef", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "439a888831ff7b2c1f4e59af8bb4a30290e823cc77491b933cbc6ea5d1f7d0ef", kill_on_drop: false }`
[INFO] [stdout] 439a888831ff7b2c1f4e59af8bb4a30290e823cc77491b933cbc6ea5d1f7d0ef
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 1211acb6c085c2fde22c495d16fcbc881b888c4348b2fdef6e8956b48c1b3fe3
[INFO] running `Command { std: "docker" "start" "-a" "1211acb6c085c2fde22c495d16fcbc881b888c4348b2fdef6e8956b48c1b3fe3", kill_on_drop: false }`
[INFO] [stderr]    Compiling libass-sys v0.1.1
[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/libass-sys-0.1.1/src/lib.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(c_variadic)]
[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 `libass-sys`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "1211acb6c085c2fde22c495d16fcbc881b888c4348b2fdef6e8956b48c1b3fe3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1211acb6c085c2fde22c495d16fcbc881b888c4348b2fdef6e8956b48c1b3fe3", kill_on_drop: false }`
[INFO] [stdout] 1211acb6c085c2fde22c495d16fcbc881b888c4348b2fdef6e8956b48c1b3fe3