[INFO] cloning repository https://github.com/Cobrand/tcp_minigame
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Cobrand/tcp_minigame" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCobrand%2Ftcp_minigame", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCobrand%2Ftcp_minigame'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] a6dfa9b02eb15447c85f5a65c4637e370b0d9ec3
[INFO] testing Cobrand/tcp_minigame against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FCobrand%2Ftcp_minigame" "/workspace/builds/worker-5/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Cobrand/tcp_minigame on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Cobrand/tcp_minigame
[INFO] finished tweaking git repo https://github.com/Cobrand/tcp_minigame
[INFO] tweaked toml for git repo https://github.com/Cobrand/tcp_minigame written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/Cobrand/tcp_minigame already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 94b40713b69ad13b1595f5303effbbfae4a7031fd1dd43edc699f372af54b8f6
[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" "94b40713b69ad13b1595f5303effbbfae4a7031fd1dd43edc699f372af54b8f6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "94b40713b69ad13b1595f5303effbbfae4a7031fd1dd43edc699f372af54b8f6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "94b40713b69ad13b1595f5303effbbfae4a7031fd1dd43edc699f372af54b8f6", kill_on_drop: false }`
[INFO] [stdout] 94b40713b69ad13b1595f5303effbbfae4a7031fd1dd43edc699f372af54b8f6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] aa8be4fd2fa1cbbdbfdbc8f63b894411af46527745eaaf0a4c55b61737919e5c
[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" "aa8be4fd2fa1cbbdbfdbc8f63b894411af46527745eaaf0a4c55b61737919e5c", kill_on_drop: false }`
[INFO] [stderr]    Compiling num-traits v0.1.36
[INFO] [stderr]    Compiling gcc v0.3.39
[INFO] [stderr]    Compiling quote v0.3.10
[INFO] [stderr]    Compiling backtrace v0.3.0
[INFO] [stderr]    Compiling sdl2-sys v0.27.0
[INFO] [stderr]    Compiling cfg-if v0.1.0
[INFO] [stderr]    Compiling rustc-demangle v0.1.3
[INFO] [stderr]    Compiling byteorder v0.5.3
[INFO] [stderr]    Compiling serde v0.8.19
[INFO] [stderr]    Compiling dbghelp-sys v0.2.0
[INFO] [stderr]    Compiling rand v0.3.15
[INFO] [stderr]    Compiling syn v0.10.3
[INFO] [stderr]    Compiling num-integer v0.1.32
[INFO] [stderr]    Compiling backtrace-sys v0.1.5
[INFO] [stderr]    Compiling num-iter v0.1.32
[INFO] [stderr]    Compiling num v0.1.36
[INFO] [stderr]    Compiling sdl2 v0.27.0
[INFO] [stderr]    Compiling serde_codegen_internals v0.11.1
[INFO] [stderr]    Compiling error-chain v0.7.1
[INFO] [stderr]    Compiling serde_codegen v0.8.19
[INFO] [stderr]    Compiling bincode v0.6.0
[INFO] [stderr]    Compiling serde_derive v0.8.19
[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/serde_derive-0.8.19/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro, proc_macro_lib)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `proc_macro` has been stable since 1.29.0 and no longer requires an attribute to enable
[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 `serde_derive` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "aa8be4fd2fa1cbbdbfdbc8f63b894411af46527745eaaf0a4c55b61737919e5c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aa8be4fd2fa1cbbdbfdbc8f63b894411af46527745eaaf0a4c55b61737919e5c", kill_on_drop: false }`
[INFO] [stdout] aa8be4fd2fa1cbbdbfdbc8f63b894411af46527745eaaf0a4c55b61737919e5c