[INFO] cloning repository https://github.com/mogendi/ping_pong
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/mogendi/ping_pong" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmogendi%2Fping_pong", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmogendi%2Fping_pong'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 0a6f6d63d861ef3d01d84c577971a5d9872011b5
[INFO] testing mogendi/ping_pong against beta-2026-04-21 for beta-1.96-2
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmogendi%2Fping_pong" "/workspace/builds/worker-0-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0-tc2/source'...
[INFO] [stderr] done.
[INFO] started tweaking git repo https://github.com/mogendi/ping_pong
[INFO] finished tweaking git repo https://github.com/mogendi/ping_pong
[INFO] tweaked toml for git repo https://github.com/mogendi/ping_pong written to /workspace/builds/worker-0-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/mogendi/ping_pong 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/mogendi/ping_pong 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] warning: the cargo feature `edition2021` has been stabilized in the 1.56 release and is no longer necessary to be listed in the manifest
[INFO] [stderr]   See https://doc.rust-lang.org/beta/cargo/reference/manifest.html#the-edition-field for more information about using this feature.
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] 8c120a90a700ff71b098fa15b3414f927bf1fb7e4b2aa0e39312958e0f14c0ce
[INFO] running `Command { std: "docker" "start" "-a" "8c120a90a700ff71b098fa15b3414f927bf1fb7e4b2aa0e39312958e0f14c0ce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8c120a90a700ff71b098fa15b3414f927bf1fb7e4b2aa0e39312958e0f14c0ce", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8c120a90a700ff71b098fa15b3414f927bf1fb7e4b2aa0e39312958e0f14c0ce", kill_on_drop: false }`
[INFO] [stdout] 8c120a90a700ff71b098fa15b3414f927bf1fb7e4b2aa0e39312958e0f14c0ce
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-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] b8b2588f50e090656632ee4158fee1bad3cf89dfe2d2c788d11f7aacc407f5ab
[INFO] running `Command { std: "docker" "start" "-a" "b8b2588f50e090656632ee4158fee1bad3cf89dfe2d2c788d11f7aacc407f5ab", kill_on_drop: false }`
[INFO] [stderr] warning: the cargo feature `edition2021` has been stabilized in the 1.56 release and is no longer necessary to be listed in the manifest
[INFO] [stderr]   See https://doc.rust-lang.org/beta/cargo/reference/manifest.html#the-edition-field for more information about using this feature.
[INFO] [stderr]    Compiling proc-macro2 v1.0.36
[INFO] [stderr]    Compiling unicode-xid v0.2.2
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling syn v1.0.84
[INFO] [stderr]    Compiling libc v0.2.112
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling unicode-width v0.1.9
[INFO] [stderr]    Compiling unicode-segmentation v1.8.0
[INFO] [stderr]    Compiling strsim v0.8.0
[INFO] [stderr]    Compiling crc32fast v1.3.0
[INFO] [stderr]    Compiling vec_map v0.8.2
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling quote v1.0.14
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling clap v2.34.0
[INFO] [stderr]    Compiling structopt-derive v0.4.18
[INFO] [stderr]    Compiling structopt v0.3.25
[INFO] [stderr]    Compiling ping_pong v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(drain_filter)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `self`
[INFO] [stdout]  --> src/chunk.rs:1:25
[INFO] [stdout]   |
[INFO] [stdout] 1 | use crate::chunk_type::{self, ChunkType};
[INFO] [stdout]   |                         ^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `drain_filter`
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(drain_filter)]
[INFO] [stdout]   |            ^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout] help: there is a feature with a similar name: `option_filter`
[INFO] [stdout]   |
[INFO] [stdout] 1 - #![feature(drain_filter)]
[INFO] [stdout] 1 + #![feature(option_filter)]
[INFO] [stdout]   |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0599]: no method named `drain_filter` found for struct `Vec<Chunk>` in the current scope
[INFO] [stdout]   --> src/png.rs:57:14
[INFO] [stdout]    |
[INFO] [stdout] 55 |           let removed_chunks: Vec<_> = self
[INFO] [stdout]    |  ______________________________________-
[INFO] [stdout] 56 | |             .chunks
[INFO] [stdout] 57 | |             .drain_filter(|chunk| chunk.chunk_type().chunk_type == chunk_type.as_bytes())
[INFO] [stdout]    | |             -^^^^^^^^^^^^ method not found in `Vec<Chunk>`
[INFO] [stdout]    | |_____________|
[INFO] [stdout]    |
[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 `ping_pong` (bin "ping_pong") due to 3 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "b8b2588f50e090656632ee4158fee1bad3cf89dfe2d2c788d11f7aacc407f5ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b8b2588f50e090656632ee4158fee1bad3cf89dfe2d2c788d11f7aacc407f5ab", kill_on_drop: false }`
[INFO] [stdout] b8b2588f50e090656632ee4158fee1bad3cf89dfe2d2c788d11f7aacc407f5ab
