[INFO] cloning repository https://github.com/AlexW-GH/rustos
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/AlexW-GH/rustos" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAlexW-GH%2Frustos", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAlexW-GH%2Frustos'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 91ec2179b3a501c093840ea22b34ec887910721c
[INFO] testing AlexW-GH/rustos against master#99e3aef02079e9c10583638520cd0c134dc3a01d for pr-85530
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FAlexW-GH%2Frustos" "/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/AlexW-GH/rustos on toolchain 99e3aef02079e9c10583638520cd0c134dc3a01d
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/AlexW-GH/rustos
[INFO] finished tweaking git repo https://github.com/AlexW-GH/rustos
[INFO] tweaked toml for git repo https://github.com/AlexW-GH/rustos written to /workspace/builds/worker-10/source/Cargo.toml
[INFO] crate git repo https://github.com/AlexW-GH/rustos already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "fetch" "--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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 956aa225955bbc877ae4323814f03830437f769f0564ff9c958977e7d29ab3f0
[INFO] running `Command { std: "docker" "start" "-a" "956aa225955bbc877ae4323814f03830437f769f0564ff9c958977e7d29ab3f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "956aa225955bbc877ae4323814f03830437f769f0564ff9c958977e7d29ab3f0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "956aa225955bbc877ae4323814f03830437f769f0564ff9c958977e7d29ab3f0", kill_on_drop: false }`
[INFO] [stdout] 956aa225955bbc877ae4323814f03830437f769f0564ff9c958977e7d29ab3f0
[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=forbid" "-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@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+99e3aef02079e9c10583638520cd0c134dc3a01d" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9a7e3fd136abde64ab3b84491f5b95726e8b1aec54517cd9cb6f5da523a8593e
[INFO] running `Command { std: "docker" "start" "-a" "9a7e3fd136abde64ab3b84491f5b95726e8b1aec54517cd9cb6f5da523a8593e", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling rlibc v1.0.0
[INFO] [stderr]    Compiling rustos v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0522]: definition of an unknown language item: `panic_fmt`
[INFO] [stdout]   --> src/lib.rs:24:1
[INFO] [stdout]    |
[INFO] [stdout] 24 | #[lang = "panic_fmt"] #[no_mangle] pub extern fn panic_fmt() -> ! {loop{}}
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^ definition of unknown language item `panic_fmt`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: `#[panic_handler]` function required, but not found
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0522`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `rustos`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "9a7e3fd136abde64ab3b84491f5b95726e8b1aec54517cd9cb6f5da523a8593e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9a7e3fd136abde64ab3b84491f5b95726e8b1aec54517cd9cb6f5da523a8593e", kill_on_drop: false }`
[INFO] [stdout] 9a7e3fd136abde64ab3b84491f5b95726e8b1aec54517cd9cb6f5da523a8593e