[INFO] fetching crate niobium 0.0.0...
[INFO] testing niobium-0.0.0 against beta-2021-09-08 for beta-1.56-1
[INFO] extracting crate niobium 0.0.0 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate niobium 0.0.0 on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate niobium 0.0.0
[INFO] finished tweaking crates.io crate niobium 0.0.0
[INFO] tweaked toml for crates.io crate niobium 0.0.0 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate crates.io crate niobium 0.0.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1c39508ed84fe798504613fdd95f9c530efb9f820be286f62b7bb037dbc3155b
[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" "1c39508ed84fe798504613fdd95f9c530efb9f820be286f62b7bb037dbc3155b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1c39508ed84fe798504613fdd95f9c530efb9f820be286f62b7bb037dbc3155b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c39508ed84fe798504613fdd95f9c530efb9f820be286f62b7bb037dbc3155b", kill_on_drop: false }`
[INFO] [stdout] 1c39508ed84fe798504613fdd95f9c530efb9f820be286f62b7bb037dbc3155b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "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] 12e78954dc11bb9d9c60744611bf8ed5a11634d4847e27f2bdd3ecca0972f77e
[INFO] running `Command { std: "docker" "start" "-a" "12e78954dc11bb9d9c60744611bf8ed5a11634d4847e27f2bdd3ecca0972f77e", kill_on_drop: false }`
[INFO] [stderr]    Compiling niobium v0.0.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.06s
[INFO] running `Command { std: "docker" "inspect" "12e78954dc11bb9d9c60744611bf8ed5a11634d4847e27f2bdd3ecca0972f77e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "12e78954dc11bb9d9c60744611bf8ed5a11634d4847e27f2bdd3ecca0972f77e", kill_on_drop: false }`
[INFO] [stdout] 12e78954dc11bb9d9c60744611bf8ed5a11634d4847e27f2bdd3ecca0972f77e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 63b6e3fe879720273083f1cb43ff6c5c59013eab6586f2674e16bf7f61640301
[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" "63b6e3fe879720273083f1cb43ff6c5c59013eab6586f2674e16bf7f61640301", kill_on_drop: false }`
[INFO] [stderr]    Compiling niobium v0.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> examples/hello_magic.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(start)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: language item required, but not found: `eh_personality`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 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 `niobium` due to 3 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "63b6e3fe879720273083f1cb43ff6c5c59013eab6586f2674e16bf7f61640301", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "63b6e3fe879720273083f1cb43ff6c5c59013eab6586f2674e16bf7f61640301", kill_on_drop: false }`
[INFO] [stdout] 63b6e3fe879720273083f1cb43ff6c5c59013eab6586f2674e16bf7f61640301