[INFO] fetching crate py-ast 0.0.4...
[INFO] testing py-ast-0.0.4 against beta-2025-10-28 for beta-1.92-2
[INFO] extracting crate py-ast 0.0.4 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate py-ast 0.0.4
[INFO] finished tweaking crates.io crate py-ast 0.0.4
[INFO] tweaked toml for crates.io crate py-ast 0.0.4 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate py-ast 0.0.4 on toolchain beta-2025-10-28
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-10-28" "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-2025-10-28" "generate-lockfile" "--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]      Locking 29 packages to latest compatible versions
[INFO] [stderr]       Adding terl v0.0.3 (available: v0.0.4)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-10-28" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-10-28" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] ac56085e07377af19473b82c3a4bfac4ce3e2232530244daaf4290d867380907
[INFO] running `Command { std: "docker" "start" "-a" "ac56085e07377af19473b82c3a4bfac4ce3e2232530244daaf4290d867380907", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ac56085e07377af19473b82c3a4bfac4ce3e2232530244daaf4290d867380907", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ac56085e07377af19473b82c3a4bfac4ce3e2232530244daaf4290d867380907", kill_on_drop: false }`
[INFO] [stdout] ac56085e07377af19473b82c3a4bfac4ce3e2232530244daaf4290d867380907
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-10-28" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d639200d7d6b507075861982c910e5c252b01216c1ee30c83163676149ff9f1f
[INFO] running `Command { std: "docker" "start" "-a" "d639200d7d6b507075861982c910e5c252b01216c1ee30c83163676149ff9f1f", kill_on_drop: false }`
[INFO] [stderr]    Compiling colored v2.2.0
[INFO] [stderr]    Compiling terl v0.0.3
[INFO] [stderr]    Compiling py-lex v0.0.3
[INFO] [stderr]    Compiling py-ir v0.0.4
[INFO] [stderr]    Compiling py-declare v0.0.4
[INFO] [stderr]    Compiling py-ast v0.0.4 (/opt/rustwide/workdir)
[INFO] [stdout] error: let chains are only allowed in Rust 2024 or later
[INFO] [stdout]    --> src/parse/expr.rs:300:28
[INFO] [stdout]     |
[INFO] [stdout] 300 |                         && let Some(rb) = p.r#match(RPU(Operators::BracketR)).apply(mapper::Try)?
[INFO] [stdout]     |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(let_chains)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `let_chains` has been stable since `1.88.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `let_chains` has been stable since 1.88.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(let_chains)]
[INFO] [stdout]   |            ^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `py-ast` (lib) due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "d639200d7d6b507075861982c910e5c252b01216c1ee30c83163676149ff9f1f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d639200d7d6b507075861982c910e5c252b01216c1ee30c83163676149ff9f1f", kill_on_drop: false }`
[INFO] [stdout] d639200d7d6b507075861982c910e5c252b01216c1ee30c83163676149ff9f1f