[INFO] cloning repository https://github.com/julian-goldsmith/osdev
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/julian-goldsmith/osdev" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjulian-goldsmith%2Fosdev", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjulian-goldsmith%2Fosdev'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] ddca462da526ef4de093a0b5c7ce2842f9d6977d
[INFO] testing julian-goldsmith/osdev against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fjulian-goldsmith%2Fosdev" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/julian-goldsmith/osdev 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/julian-goldsmith/osdev
[INFO] finished tweaking git repo https://github.com/julian-goldsmith/osdev
[INFO] tweaked toml for git repo https://github.com/julian-goldsmith/osdev written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/julian-goldsmith/osdev 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-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] 64edac5a381022fc17af96bf8c1b3f9dc9a316ce5f1166793c261913dd3b1946
[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" "64edac5a381022fc17af96bf8c1b3f9dc9a316ce5f1166793c261913dd3b1946", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "64edac5a381022fc17af96bf8c1b3f9dc9a316ce5f1166793c261913dd3b1946", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "64edac5a381022fc17af96bf8c1b3f9dc9a316ce5f1166793c261913dd3b1946", kill_on_drop: false }`
[INFO] [stdout] 64edac5a381022fc17af96bf8c1b3f9dc9a316ce5f1166793c261913dd3b1946
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] b5e821ca2b679a7a3fa24d2dfca19cf2c7700453af6c79b2a1d543aca2041123
[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" "b5e821ca2b679a7a3fa24d2dfca19cf2c7700453af6c79b2a1d543aca2041123", kill_on_drop: false }`
[INFO] [stderr]    Compiling rlibc v1.0.0
[INFO] [stderr]    Compiling kernel v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(panic_implementation)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: subsumed by `#[panic_handler]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: cannot find attribute `panic_implementation` in this scope
[INFO] [stdout]   --> src/lib.rs:24:3
[INFO] [stdout]    |
[INFO] [stdout] 24 | #[panic_implementation]
[INFO] [stdout]    |   ^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(panic_implementation)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `core::fmt::Write`
[INFO] [stdout]  --> src/lib.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use core::fmt::Write;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: `#[panic_handler]` function required, but not found
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 previous errors; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0557.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `kernel` due to 5 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "b5e821ca2b679a7a3fa24d2dfca19cf2c7700453af6c79b2a1d543aca2041123", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b5e821ca2b679a7a3fa24d2dfca19cf2c7700453af6c79b2a1d543aca2041123", kill_on_drop: false }`
[INFO] [stdout] b5e821ca2b679a7a3fa24d2dfca19cf2c7700453af6c79b2a1d543aca2041123