[INFO] fetching crate reckon 0.1.0...
[INFO] testing reckon-0.1.0 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate reckon 0.1.0 into /workspace/builds/worker-6-tc2/source
[INFO] started tweaking crates.io crate reckon 0.1.0
[INFO] finished tweaking crates.io crate reckon 0.1.0
[INFO] tweaked toml for crates.io crate reckon 0.1.0 written to /workspace/builds/worker-6-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate reckon 0.1.0 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] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2026-04-21" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 11 packages to latest compatible versions
[INFO] [stderr]       Adding regex v0.1.80 (available: v1.12.3)
[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] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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] 6dde604c30b9a8a25d23ebe3e6d3dc898b7d0b5fe590c2e6939c2663e9ce16c0
[INFO] running `Command { std: "docker" "start" "-a" "6dde604c30b9a8a25d23ebe3e6d3dc898b7d0b5fe590c2e6939c2663e9ce16c0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6dde604c30b9a8a25d23ebe3e6d3dc898b7d0b5fe590c2e6939c2663e9ce16c0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6dde604c30b9a8a25d23ebe3e6d3dc898b7d0b5fe590c2e6939c2663e9ce16c0", kill_on_drop: false }`
[INFO] [stdout] 6dde604c30b9a8a25d23ebe3e6d3dc898b7d0b5fe590c2e6939c2663e9ce16c0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6-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" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] a51be53e14872fe2d1713fb022e50972e80129abf10ad7c1f2d74b05ec314086
[INFO] running `Command { std: "docker" "start" "-a" "a51be53e14872fe2d1713fb022e50972e80129abf10ad7c1f2d74b05ec314086", kill_on_drop: false }`
[INFO] [stderr] warning: `package.edition` is unspecified, defaulting to `2015` while the latest is `2024`
[INFO] [stderr]    Compiling libc v0.2.186
[INFO] [stderr]    Compiling winapi-build v0.1.1
[INFO] [stderr]    Compiling winapi v0.2.8
[INFO] [stderr]    Compiling regex-syntax v0.3.9
[INFO] [stderr]    Compiling utf8-ranges v0.1.3
[INFO] [stderr]    Compiling kernel32-sys v0.2.2
[INFO] [stderr]    Compiling memchr v0.1.11
[INFO] [stderr]    Compiling thread-id v2.0.0
[INFO] [stderr]    Compiling thread_local v0.2.7
[INFO] [stderr]    Compiling aho-corasick v0.5.3
[INFO] [stderr]    Compiling regex v0.1.80
[INFO] [stderr]    Compiling reckon v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(io)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `io`
[INFO] [stdout]  --> src/lib.rs:9:12
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(io)]
[INFO] [stdout]   |            ^^
[INFO] [stdout]   |
[INFO] [stdout] help: there is a feature with a similar name: `ip`
[INFO] [stdout]   |
[INFO] [stdout] 9 - #![feature(io)]
[INFO] [stdout] 9 + #![feature(ip)]
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `chars` found for mutable reference `&mut ChildStdout` in the current scope
[INFO] [stdout]    --> src/base.rs:154:28
[INFO] [stdout]     |
[INFO] [stdout] 154 |         let mut c = stdout.chars();
[INFO] [stdout]     |                            ^^^^^ method not found in `&mut ChildStdout`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/base.rs:69:13
[INFO] [stdout]    |
[INFO] [stdout] 69 |         let mut stdin = self.child.stdin.as_mut().unwrap();
[INFO] [stdout]    |             ----^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_mut)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0599, E0635.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `reckon` (lib) due to 3 previous errors; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "a51be53e14872fe2d1713fb022e50972e80129abf10ad7c1f2d74b05ec314086", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a51be53e14872fe2d1713fb022e50972e80129abf10ad7c1f2d74b05ec314086", kill_on_drop: false }`
[INFO] [stdout] a51be53e14872fe2d1713fb022e50972e80129abf10ad7c1f2d74b05ec314086
