[INFO] fetching crate prongs 0.0.5...
[INFO] testing prongs-0.0.5 against beta-2026-04-21 for beta-1.96-2
[INFO] extracting crate prongs 0.0.5 into /workspace/builds/worker-2-tc2/source
[INFO] started tweaking crates.io crate prongs 0.0.5
[INFO] finished tweaking crates.io crate prongs 0.0.5
[INFO] tweaked toml for crates.io crate prongs 0.0.5 written to /workspace/builds/worker-2-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate prongs 0.0.5 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]      Locking 33 packages to latest compatible versions
[INFO] [stderr]       Adding bitflags v1.3.2 (available: v2.11.1)
[INFO] [stderr]       Adding gilrs v0.6.3 (available: v0.11.1)
[INFO] [stderr]       Adding piston v0.41.0 (available: v1.0.0)
[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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 72808e55b97887a86859fa7dffcf5d447487f5a43562d154b2de5258095f3aac
[INFO] running `Command { std: "docker" "start" "-a" "72808e55b97887a86859fa7dffcf5d447487f5a43562d154b2de5258095f3aac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "72808e55b97887a86859fa7dffcf5d447487f5a43562d154b2de5258095f3aac", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "72808e55b97887a86859fa7dffcf5d447487f5a43562d154b2de5258095f3aac", kill_on_drop: false }`
[INFO] [stdout] 72808e55b97887a86859fa7dffcf5d447487f5a43562d154b2de5258095f3aac
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 669a902eac609a55c6b7819e34707b734496d698ae0fbf6d1331cf7eb5b8c0b7
[INFO] running `Command { std: "docker" "start" "-a" "669a902eac609a55c6b7819e34707b734496d698ae0fbf6d1331cf7eb5b8c0b7", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.106
[INFO] [stderr]    Compiling quote v1.0.45
[INFO] [stderr]    Compiling serde_core v1.0.228
[INFO] [stderr]    Compiling serde v1.0.228
[INFO] [stderr]    Compiling syn v2.0.117
[INFO] [stderr]    Compiling serde_derive v1.0.228
[INFO] [stderr]    Compiling prongs v0.0.5 (/opt/rustwide/workdir)
[INFO] [stdout] error: No backend selected, use features=<backend> in Cargo.toml or --features <backend> when building directly.
[INFO] [stdout]   --> src/lib.rs:14:1
[INFO] [stdout]    |
[INFO] [stdout] 14 | compile_error!("No backend selected, use features=<backend> in Cargo.toml or --features <backend> when building directly.");
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `prongs` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "669a902eac609a55c6b7819e34707b734496d698ae0fbf6d1331cf7eb5b8c0b7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "669a902eac609a55c6b7819e34707b734496d698ae0fbf6d1331cf7eb5b8c0b7", kill_on_drop: false }`
[INFO] [stdout] 669a902eac609a55c6b7819e34707b734496d698ae0fbf6d1331cf7eb5b8c0b7
