[INFO] cloning repository https://github.com/denysvitali/vbox-proxy-server
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/denysvitali/vbox-proxy-server" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdenysvitali%2Fvbox-proxy-server", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdenysvitali%2Fvbox-proxy-server'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e98b11902ac97ddb5d0d3e5abc1274ac91265565
[INFO] testing denysvitali/vbox-proxy-server against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fdenysvitali%2Fvbox-proxy-server" "/workspace/builds/worker-1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/denysvitali/vbox-proxy-server on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/denysvitali/vbox-proxy-server
[INFO] finished tweaking git repo https://github.com/denysvitali/vbox-proxy-server
[INFO] tweaked toml for git repo https://github.com/denysvitali/vbox-proxy-server written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] crate git repo https://github.com/denysvitali/vbox-proxy-server already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "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-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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 18fc95b932a030af4d1f062ce8698ab522bb366fbe90127aa9b4ace0694ea2f9
[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" "18fc95b932a030af4d1f062ce8698ab522bb366fbe90127aa9b4ace0694ea2f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "18fc95b932a030af4d1f062ce8698ab522bb366fbe90127aa9b4ace0694ea2f9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "18fc95b932a030af4d1f062ce8698ab522bb366fbe90127aa9b4ace0694ea2f9", kill_on_drop: false }`
[INFO] [stdout] 18fc95b932a030af4d1f062ce8698ab522bb366fbe90127aa9b4ace0694ea2f9
[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" "rustops/crates-build-env@sha256:c8ac004eab7d63a0ad09a2dde3d3353ba464f767bee4de425dc8f74c46a1905e" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "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] 2de1a21f6968a143ccfd53d700acf5d60b23f5f65737fd61aa862fb91c90e1d3
[INFO] running `Command { std: "docker" "start" "-a" "2de1a21f6968a143ccfd53d700acf5d60b23f5f65737fd61aa862fb91c90e1d3", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.30
[INFO] [stderr]    Compiling version_check v0.1.3
[INFO] [stderr]    Compiling rayon-core v1.2.1
[INFO] [stderr]    Compiling scopeguard v0.3.2
[INFO] [stderr]    Compiling either v1.1.0
[INFO] [stderr]    Compiling futures v0.1.15
[INFO] [stderr]    Compiling matches v0.1.6
[INFO] [stderr]    Compiling unicode-normalization v0.1.5
[INFO] [stderr]    Compiling yansi v0.3.3
[INFO] [stderr]    Compiling gcc v0.3.53
[INFO] [stderr]    Compiling safemem v0.2.0
[INFO] [stderr]    Compiling percent-encoding v1.0.0
[INFO] [stderr]    Compiling byteorder v1.1.0
[INFO] [stderr]    Compiling serde v1.0.11
[INFO] [stderr]    Compiling log v0.3.8
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/yansi-0.3.3/src/lib.rs:1:32
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(feature="nightly", feature(const_fn))]
[INFO] [stdout]   |                                ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling untrusted v0.5.1
[INFO] [stderr]    Compiling httparse v1.2.3
[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 `yansi`
[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" "2de1a21f6968a143ccfd53d700acf5d60b23f5f65737fd61aa862fb91c90e1d3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "2de1a21f6968a143ccfd53d700acf5d60b23f5f65737fd61aa862fb91c90e1d3", kill_on_drop: false }`
[INFO] [stdout] 2de1a21f6968a143ccfd53d700acf5d60b23f5f65737fd61aa862fb91c90e1d3