[INFO] fetching crate mantle-rpc 0.1.1...
[INFO] testing mantle-rpc-0.1.1 against beta-2025-09-21 for beta-1.91-3
[INFO] extracting crate mantle-rpc 0.1.1 into /workspace/builds/worker-4-tc2/source
[INFO] started tweaking crates.io crate mantle-rpc 0.1.1
[INFO] finished tweaking crates.io crate mantle-rpc 0.1.1
[INFO] tweaked toml for crates.io crate mantle-rpc 0.1.1 written to /workspace/builds/worker-4-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate mantle-rpc 0.1.1 on toolchain beta-2025-09-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "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-2025-09-21" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 57 packages to latest compatible versions
[INFO] [stderr]       Adding libflate v0.1.27 (available: v2.1.0)
[INFO] [stderr]       Adding url v1.7.2 (available: v2.5.7)
[INFO] [stderr]       Adding walrus v0.8.0 (available: v0.23.3)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 76b672ed8f9c43169b9a00f243568c800cacdd2e9751554a0de34a2326c77d45
[INFO] running `Command { std: "docker" "start" "-a" "76b672ed8f9c43169b9a00f243568c800cacdd2e9751554a0de34a2326c77d45", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "76b672ed8f9c43169b9a00f243568c800cacdd2e9751554a0de34a2326c77d45", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "76b672ed8f9c43169b9a00f243568c800cacdd2e9751554a0de34a2326c77d45", kill_on_drop: false }`
[INFO] [stdout] 76b672ed8f9c43169b9a00f243568c800cacdd2e9751554a0de34a2326c77d45
[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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2025-09-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] bc293aa3b4be51e63066b845687e5a6eb8d79b677da07c0d4f0421936f846b3b
[INFO] running `Command { std: "docker" "start" "-a" "bc293aa3b4be51e63066b845687e5a6eb8d79b677da07c0d4f0421936f846b3b", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v2.0.106
[INFO] [stderr]    Compiling serde_derive v1.0.228
[INFO] [stderr]    Compiling serde v1.0.228
[INFO] [stderr]    Compiling mantle-rpc v0.1.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0557]: feature has been removed
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(box_syntax)]
[INFO] [stdout]   |            ^^^^^^^^^^ feature has been removed
[INFO] [stdout]   |
[INFO] [stdout]   = note: removed in 1.70.0; see <https://github.com/rust-lang/rust/pull/108471> for more information
[INFO] [stdout]   = note: replaced with `#[rustc_box]`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0557`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `mantle-rpc` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "bc293aa3b4be51e63066b845687e5a6eb8d79b677da07c0d4f0421936f846b3b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "bc293aa3b4be51e63066b845687e5a6eb8d79b677da07c0d4f0421936f846b3b", kill_on_drop: false }`
[INFO] [stdout] bc293aa3b4be51e63066b845687e5a6eb8d79b677da07c0d4f0421936f846b3b