[INFO] cloning repository https://github.com/luyikk/tcp_server
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/luyikk/tcp_server" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fluyikk%2Ftcp_server", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fluyikk%2Ftcp_server'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 4e4bbe8fbc0f937e36be42b462c85d0e4fbb8be0
[INFO] testing luyikk/tcp_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%2Fluyikk%2Ftcp_server" "/workspace/builds/worker-10/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-10/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/luyikk/tcp_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/luyikk/tcp_server
[INFO] finished tweaking git repo https://github.com/luyikk/tcp_server
[INFO] tweaked toml for git repo https://github.com/luyikk/tcp_server written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate git repo https://github.com/luyikk/tcp_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-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "+1.49.0" "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] 7086f58325d999961dba3a19af028e88ae19dc03cc0139249b20e27b7bf40ee4
[INFO] running `Command { std: "docker" "start" "-a" "7086f58325d999961dba3a19af028e88ae19dc03cc0139249b20e27b7bf40ee4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7086f58325d999961dba3a19af028e88ae19dc03cc0139249b20e27b7bf40ee4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7086f58325d999961dba3a19af028e88ae19dc03cc0139249b20e27b7bf40ee4", kill_on_drop: false }`
[INFO] [stdout] 7086f58325d999961dba3a19af028e88ae19dc03cc0139249b20e27b7bf40ee4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-10/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" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 3de9870d863d426ec785914727263501971f7b9b901023b5ac1ee400d7b4da99
[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" "3de9870d863d426ec785914727263501971f7b9b901023b5ac1ee400d7b4da99", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.79
[INFO] [stderr]    Compiling syn v1.0.45
[INFO] [stderr]    Compiling futures-micro v0.3.1
[INFO] [stderr]    Compiling paste v1.0.4
[INFO] [stderr]    Compiling tokio v1.0.1
[INFO] [stderr]    Compiling async-oneshot v0.4.2
[INFO] [stderr]    Compiling data-rw v0.2.1
[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/data-rw-0.2.1/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(optin_builtin_traits,negative_impls)]
[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 `data-rw`
[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" "3de9870d863d426ec785914727263501971f7b9b901023b5ac1ee400d7b4da99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3de9870d863d426ec785914727263501971f7b9b901023b5ac1ee400d7b4da99", kill_on_drop: false }`
[INFO] [stdout] 3de9870d863d426ec785914727263501971f7b9b901023b5ac1ee400d7b4da99