[INFO] cloning repository https://github.com/lutzer/midi_clock
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/lutzer/midi_clock" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flutzer%2Fmidi_clock", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flutzer%2Fmidi_clock'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] d3ebc945086560f6ca5b397deefd9be3c443d17f
[INFO] documenting lutzer/midi_clock 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%2Flutzer%2Fmidi_clock" "/workspace/builds/worker-107/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-107/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/lutzer/midi_clock 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-107/source/.cargo/config
[INFO] started tweaking git repo https://github.com/lutzer/midi_clock
[INFO] finished tweaking git repo https://github.com/lutzer/midi_clock
[INFO] tweaked toml for git repo https://github.com/lutzer/midi_clock written to /workspace/builds/worker-107/source/Cargo.toml
[INFO] crate git repo https://github.com/lutzer/midi_clock 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 aligned v0.3.5
[INFO] [stderr]   Downloaded linked_list_allocator v0.8.11
[INFO] [stderr]   Downloaded cortex-m-rt-macros v0.6.15
[INFO] [stderr]   Downloaded cortex-m-rt v0.6.15
[INFO] [stderr]   Downloaded hash32 v0.2.1
[INFO] [stderr]   Downloaded cortex-m v0.7.3
[INFO] [stderr]   Downloaded atomic-polyfill v0.1.2
[INFO] [stderr]   Downloaded alloc-cortex-m v0.4.1
[INFO] [stderr]   Downloaded heapless v0.7.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/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] 45279c198199c1f880f7dd01d0797a5661ceb8a8bd4d8658f22cd14abfef5643
[INFO] running `Command { std: "docker" "start" "-a" "45279c198199c1f880f7dd01d0797a5661ceb8a8bd4d8658f22cd14abfef5643", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "45279c198199c1f880f7dd01d0797a5661ceb8a8bd4d8658f22cd14abfef5643", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "45279c198199c1f880f7dd01d0797a5661ceb8a8bd4d8658f22cd14abfef5643", kill_on_drop: false }`
[INFO] [stdout] 45279c198199c1f880f7dd01d0797a5661ceb8a8bd4d8658f22cd14abfef5643
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-107/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] ac9f3f3735c1f1998f512a84188981dd2894d0793c7f389918b03eac9f8ecc22
[INFO] running `Command { std: "docker" "start" "-a" "ac9f3f3735c1f1998f512a84188981dd2894d0793c7f389918b03eac9f8ecc22", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling typenum v1.13.0
[INFO] [stderr]    Compiling version_check v0.9.3
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling semver v1.0.3
[INFO] [stderr]     Checking stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling cortex-m v0.7.3
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]     Checking nb v1.0.0
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]     Checking vcell v0.1.3
[INFO] [stderr]     Checking void v1.0.2
[INFO] [stderr]    Compiling cortex-m v0.6.7
[INFO] [stderr]    Compiling cortex-m-rt v0.6.15
[INFO] [stderr]     Checking bitfield v0.13.2
[INFO] [stderr]    Compiling stm32f1 v0.11.0
[INFO] [stderr]     Checking r0 v0.2.2
[INFO] [stderr]    Compiling heapless v0.7.3
[INFO] [stderr]     Checking linked_list_allocator v0.8.11
[INFO] [stderr]     Checking panic-halt v0.2.0
[INFO] [stderr]     Checking hash32 v0.2.1
[INFO] [stderr]    Compiling bare-metal v0.2.5
[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/linked_list_allocator-0.8.11/src/lib.rs:1:41
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(feature = "const_mut_refs", feature(const_mut_refs))]
[INFO] [stdout]   |                                         ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking nb v0.1.3
[INFO] [stderr]     Checking volatile-register v0.2.0
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `linked_list_allocator`
[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" "ac9f3f3735c1f1998f512a84188981dd2894d0793c7f389918b03eac9f8ecc22", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ac9f3f3735c1f1998f512a84188981dd2894d0793c7f389918b03eac9f8ecc22", kill_on_drop: false }`
[INFO] [stdout] ac9f3f3735c1f1998f512a84188981dd2894d0793c7f389918b03eac9f8ecc22
