[INFO] cloning repository https://github.com/NZqian/ning-os
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/NZqian/ning-os" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNZqian%2Fning-os", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNZqian%2Fning-os'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6977afaa96f800291826fcd35c3a6d1fb94ffe57
[INFO] documenting NZqian/ning-os against 1.54.0 for beta-1.55-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FNZqian%2Fning-os" "/workspace/builds/worker-37/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-37/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/NZqian/ning-os on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-37/source/.cargo/config.toml
[INFO] started tweaking git repo https://github.com/NZqian/ning-os
[INFO] removed 0 missing tests
[INFO] finished tweaking git repo https://github.com/NZqian/ning-os
[INFO] tweaked toml for git repo https://github.com/NZqian/ning-os written to /workspace/builds/worker-37/source/Cargo.toml
[INFO] crate git repo https://github.com/NZqian/ning-os already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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 linked_list_allocator v0.9.0
[INFO] [stderr]   Downloaded spin v0.7.1
[INFO] [stderr]   Downloaded buddy_system_allocator v0.8.0
[INFO] [stderr]   Downloaded spin v0.9.2
[INFO] [stderr]   Downloaded x86_64 v0.14.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-37/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-37/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 75b884faddfcdff5ed82c04698ac946da01e36fc00be9b3b2b63e0f0b0d911be
[INFO] running `Command { std: "docker" "start" "-a" "75b884faddfcdff5ed82c04698ac946da01e36fc00be9b3b2b63e0f0b0d911be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "75b884faddfcdff5ed82c04698ac946da01e36fc00be9b3b2b63e0f0b0d911be", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "75b884faddfcdff5ed82c04698ac946da01e36fc00be9b3b2b63e0f0b0d911be", kill_on_drop: false }`
[INFO] [stdout] 75b884faddfcdff5ed82c04698ac946da01e36fc00be9b3b2b63e0f0b0d911be
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-37/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-37/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" "RUSTDOCFLAGS=--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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c1ee02ca455c3495d41d6e8f63ec717ea28d65b3f0c2443cfb7b50a3f8c09420
[INFO] running `Command { std: "docker" "start" "-a" "c1ee02ca455c3495d41d6e8f63ec717ea28d65b3f0c2443cfb7b50a3f8c09420", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]    Compiling x86_64 v0.14.3
[INFO] [stderr]     Checking volatile v0.4.4
[INFO] [stderr]     Checking bit_field v0.9.0
[INFO] [stderr]    Compiling bootloader v0.9.18
[INFO] [stderr]     Checking spin v0.7.1
[INFO] [stderr]     Checking volatile v0.2.7
[INFO] [stderr]     Checking pc-keyboard v0.5.1
[INFO] [stderr]     Checking lazy_static v1.4.0
[INFO] [stderr]     Checking buddy_system_allocator v0.8.0
[INFO] [stderr]     Checking lock_api v0.4.4
[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/lock_api-0.4.4/src/lib.rs:91:34
[INFO] [stdout]    |
[INFO] [stdout] 91 | #![cfg_attr(feature = "nightly", feature(const_fn_trait_bound))]
[INFO] [stdout]    |                                  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lock_api`
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "c1ee02ca455c3495d41d6e8f63ec717ea28d65b3f0c2443cfb7b50a3f8c09420", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c1ee02ca455c3495d41d6e8f63ec717ea28d65b3f0c2443cfb7b50a3f8c09420", kill_on_drop: false }`
[INFO] [stdout] c1ee02ca455c3495d41d6e8f63ec717ea28d65b3f0c2443cfb7b50a3f8c09420
