[INFO] cloning repository https://github.com/mrsweaters/nutbutter-os
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mrsweaters/nutbutter-os" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmrsweaters%2Fnutbutter-os", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmrsweaters%2Fnutbutter-os'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d78c1c4a1180610af9ca2ec10d9a8d300caa792a
[INFO] testing mrsweaters/nutbutter-os against 1.55.0 for beta-1.56-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmrsweaters%2Fnutbutter-os" "/workspace/builds/worker-54/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-54/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/mrsweaters/nutbutter-os 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/mrsweaters/nutbutter-os
[INFO] finished tweaking git repo https://github.com/mrsweaters/nutbutter-os
[INFO] tweaked toml for git repo https://github.com/mrsweaters/nutbutter-os written to /workspace/builds/worker-54/source/Cargo.toml
[INFO] crate git repo https://github.com/mrsweaters/nutbutter-os 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded bootloader_precompiled v0.2.0
[INFO] [stderr]   Downloaded spin v0.4.9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/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] 08f15e07aaf796a88e12b3811e71c26dfbea18f7108ec339e9499b8f3c106ed2
[INFO] running `Command { std: "docker" "start" "-a" "08f15e07aaf796a88e12b3811e71c26dfbea18f7108ec339e9499b8f3c106ed2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "08f15e07aaf796a88e12b3811e71c26dfbea18f7108ec339e9499b8f3c106ed2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "08f15e07aaf796a88e12b3811e71c26dfbea18f7108ec339e9499b8f3c106ed2", kill_on_drop: false }`
[INFO] [stdout] 08f15e07aaf796a88e12b3811e71c26dfbea18f7108ec339e9499b8f3c106ed2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-54/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] aaf5eda2962a759fe6ef23ee452a562138879e6dc7e4bb750b33bad6a6a82fed
[INFO] running `Command { std: "docker" "start" "-a" "aaf5eda2962a759fe6ef23ee452a562138879e6dc7e4bb750b33bad6a6a82fed", kill_on_drop: false }`
[INFO] [stderr]    Compiling version_check v0.1.5
[INFO] [stderr]    Compiling spin v0.4.9
[INFO] [stderr]    Compiling os_bootinfo v0.2.1
[INFO] [stderr]    Compiling volatile v0.2.4
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/spin-0.4.9/src/lib.rs:6:43
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![cfg_attr(feature = "const_fn", feature(const_fn))]
[INFO] [stdout]   |                                           ^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: split into finer-grained feature gates
[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/spin-0.4.9/src/lib.rs:6:35
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![cfg_attr(feature = "const_fn", feature(const_fn))]
[INFO] [stdout]   |                                   ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[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 `spin` due to 3 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "aaf5eda2962a759fe6ef23ee452a562138879e6dc7e4bb750b33bad6a6a82fed", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aaf5eda2962a759fe6ef23ee452a562138879e6dc7e4bb750b33bad6a6a82fed", kill_on_drop: false }`
[INFO] [stdout] aaf5eda2962a759fe6ef23ee452a562138879e6dc7e4bb750b33bad6a6a82fed