[INFO] fetching crate magic-ring-buffer 0.1.0...
[INFO] testing magic-ring-buffer-0.1.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate magic-ring-buffer 0.1.0 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate magic-ring-buffer 0.1.0 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 crates.io crate magic-ring-buffer 0.1.0
[INFO] finished tweaking crates.io crate magic-ring-buffer 0.1.0
[INFO] tweaked toml for crates.io crate magic-ring-buffer 0.1.0 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[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-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" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] b53c7e4515f0a11e1edab8fcb12268198f940dc0a83e528c1c9c394dac6f92ff
[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" "b53c7e4515f0a11e1edab8fcb12268198f940dc0a83e528c1c9c394dac6f92ff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "b53c7e4515f0a11e1edab8fcb12268198f940dc0a83e528c1c9c394dac6f92ff", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b53c7e4515f0a11e1edab8fcb12268198f940dc0a83e528c1c9c394dac6f92ff", kill_on_drop: false }`
[INFO] [stdout] b53c7e4515f0a11e1edab8fcb12268198f940dc0a83e528c1c9c394dac6f92ff
[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" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9b250053300724e58edbcef7e66f992eb9e9ad1339ffe4e890152f8285e487c7
[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" "9b250053300724e58edbcef7e66f992eb9e9ad1339ffe4e890152f8285e487c7", kill_on_drop: false }`
[INFO] [stderr]    Compiling likely v0.1.0
[INFO] [stderr]    Compiling strum v0.13.0
[INFO] [stderr]    Compiling errno v0.2.7
[INFO] [stderr]    Compiling strum_macros v0.13.0
[INFO] [stderr]    Compiling file-descriptors v0.8.7
[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/file-descriptors-0.8.7/src/lib.rs:10:1
[INFO] [stdout]    |
[INFO] [stdout] 10 | #![feature(core_intrinsics)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/file-descriptors-0.8.7/src/lib.rs:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | #![feature(read_initializer)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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/file-descriptors-0.8.7/src/lib.rs:12:1
[INFO] [stdout]    |
[INFO] [stdout] 12 | #![feature(try_from)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 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 `file-descriptors` due to 4 previous errors
[INFO] running `Command { std: "docker" "inspect" "9b250053300724e58edbcef7e66f992eb9e9ad1339ffe4e890152f8285e487c7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9b250053300724e58edbcef7e66f992eb9e9ad1339ffe4e890152f8285e487c7", kill_on_drop: false }`
[INFO] [stdout] 9b250053300724e58edbcef7e66f992eb9e9ad1339ffe4e890152f8285e487c7