[INFO] fetching crate exar-server 0.1.0...
[INFO] testing exar-server-0.1.0 against beta-2021-01-01 for beta-1.50-1
[INFO] extracting crate exar-server 0.1.0 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate exar-server 0.1.0 on toolchain beta-2021-01-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate exar-server 0.1.0
[INFO] removed path dependency exar from crates.io crate exar-server 0.1.0
[INFO] removed path dependency exar-net from crates.io crate exar-server 0.1.0
[INFO] removed path dependency exar-testkit from crates.io crate exar-server 0.1.0
[INFO] finished tweaking crates.io crate exar-server 0.1.0
[INFO] tweaked toml for crates.io crate exar-server 0.1.0 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-01-01" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded indexed-line-reader v0.2.1
[INFO] [stderr]   Downloaded exar-testkit v0.1.0
[INFO] [stderr]   Downloaded exar-net v0.1.0
[INFO] [stderr]   Downloaded exar v0.1.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+beta-2021-01-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8ad0ba354ae16f9db7a13f3c33468f22f20eda452208e1b32e783f78f7059683
[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" "8ad0ba354ae16f9db7a13f3c33468f22f20eda452208e1b32e783f78f7059683", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8ad0ba354ae16f9db7a13f3c33468f22f20eda452208e1b32e783f78f7059683", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8ad0ba354ae16f9db7a13f3c33468f22f20eda452208e1b32e783f78f7059683", kill_on_drop: false }`
[INFO] [stdout] 8ad0ba354ae16f9db7a13f3c33468f22f20eda452208e1b32e783f78f7059683
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+beta-2021-01-01" "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] 7a617d8248d2018153940d52ed55844b80b0adf0a4938067f4f62b7dae1abcd1
[INFO] running `Command { std: "docker" "start" "-a" "7a617d8248d2018153940d52ed55844b80b0adf0a4938067f4f62b7dae1abcd1", kill_on_drop: false }`
[INFO] [stderr]    Compiling indexed-line-reader v0.2.1
[INFO] [stderr]    Compiling exar v0.1.0
[INFO] [stderr]    Compiling exar-net v0.1.0
[INFO] [stderr]    Compiling exar-server v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 5.42s
[INFO] running `Command { std: "docker" "inspect" "7a617d8248d2018153940d52ed55844b80b0adf0a4938067f4f62b7dae1abcd1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7a617d8248d2018153940d52ed55844b80b0adf0a4938067f4f62b7dae1abcd1", kill_on_drop: false }`
[INFO] [stdout] 7a617d8248d2018153940d52ed55844b80b0adf0a4938067f4f62b7dae1abcd1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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" "+beta-2021-01-01" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 805e2077865616995a71b14d6fdaada16e94e2db1ddb3e630530960a098060da
[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" "805e2077865616995a71b14d6fdaada16e94e2db1ddb3e630530960a098060da", kill_on_drop: false }`
[INFO] [stderr]    Compiling exar-testkit v0.1.0
[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/exar-testkit-0.1.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(const_fn)]
[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 `exar-testkit`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "805e2077865616995a71b14d6fdaada16e94e2db1ddb3e630530960a098060da", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "805e2077865616995a71b14d6fdaada16e94e2db1ddb3e630530960a098060da", kill_on_drop: false }`
[INFO] [stdout] 805e2077865616995a71b14d6fdaada16e94e2db1ddb3e630530960a098060da