[INFO] cloning repository https://github.com/Maurdekye/mnist-nn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/Maurdekye/mnist-nn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaurdekye%2Fmnist-nn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaurdekye%2Fmnist-nn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c1c979ec7116ac971de7a432222b4f5208fea3f9
[INFO] documenting Maurdekye/mnist-nn against beta-2026-04-21 for beta-1.96-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FMaurdekye%2Fmnist-nn" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/Maurdekye/mnist-nn
[INFO] finished tweaking git repo https://github.com/Maurdekye/mnist-nn
[INFO] tweaked toml for git repo https://github.com/Maurdekye/mnist-nn written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/Maurdekye/mnist-nn on toolchain beta-2026-04-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/Maurdekye/mnist-nn already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded progress-observer v3.2.0
[INFO] [stderr]   Downloaded clap_derive v4.5.3
[INFO] [stderr]   Downloaded clap v4.5.3
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 7c7a4908c8664cb31b8cede0a1c189b9470a8700e3a927b1d51256d24777e6de
[INFO] running `Command { std: "docker" "start" "-a" "7c7a4908c8664cb31b8cede0a1c189b9470a8700e3a927b1d51256d24777e6de", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "7c7a4908c8664cb31b8cede0a1c189b9470a8700e3a927b1d51256d24777e6de", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7c7a4908c8664cb31b8cede0a1c189b9470a8700e3a927b1d51256d24777e6de", kill_on_drop: false }`
[INFO] [stdout] 7c7a4908c8664cb31b8cede0a1c189b9470a8700e3a927b1d51256d24777e6de
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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" "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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2026-04-21" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5817a0c6433d94f15c72af7c8584e35f69c44614a2a54cb32724d18b7f23305e
[INFO] running `Command { std: "docker" "start" "-a" "5817a0c6433d94f15c72af7c8584e35f69c44614a2a54cb32724d18b7f23305e", kill_on_drop: false }`
[INFO] [stderr]    Compiling unicode-ident v1.0.12
[INFO] [stderr]    Compiling libc v0.2.153
[INFO] [stderr]    Compiling crossbeam-utils v0.8.19
[INFO] [stderr]    Compiling serde v1.0.197
[INFO] [stderr]     Checking utf8parse v0.2.1
[INFO] [stderr]     Checking anstyle-query v1.0.2
[INFO] [stderr]     Checking colorchoice v1.0.0
[INFO] [stderr]     Checking anstyle v1.0.6
[INFO] [stderr]     Checking strsim v0.11.0
[INFO] [stderr]    Compiling proc-macro2 v1.0.79
[INFO] [stderr]     Checking anstyle-parse v0.2.3
[INFO] [stderr]     Checking either v1.10.0
[INFO] [stderr]     Checking memchr v2.7.2
[INFO] [stderr]     Checking clap_lex v0.7.0
[INFO] [stderr]     Checking ryu v1.0.17
[INFO] [stderr]     Checking anstream v0.6.13
[INFO] [stderr]     Checking progress-observer v3.2.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/progress-observer-3.2.0/src/lib.rs:70:1
[INFO] [stdout]    |
[INFO] [stdout] 70 | #![feature(div_duration)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `progress-observer` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "5817a0c6433d94f15c72af7c8584e35f69c44614a2a54cb32724d18b7f23305e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5817a0c6433d94f15c72af7c8584e35f69c44614a2a54cb32724d18b7f23305e", kill_on_drop: false }`
[INFO] [stdout] 5817a0c6433d94f15c72af7c8584e35f69c44614a2a54cb32724d18b7f23305e