[INFO] fetching crate lightbeam 0.29.0...
[INFO] testing lightbeam-0.29.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate lightbeam 0.29.0 into /workspace/builds/worker-12/source
[INFO] validating manifest of crates.io crate lightbeam 0.29.0 on toolchain 1.55.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate lightbeam 0.29.0
[INFO] finished tweaking crates.io crate lightbeam 0.29.0
[INFO] tweaked toml for crates.io crate lightbeam 0.29.0 written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate crates.io crate lightbeam 0.29.0 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.55.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded dynasmrt v1.1.0
[INFO] [stderr]   Downloaded wat v1.0.38
[INFO] [stderr]   Downloaded dynasm v1.1.0
[INFO] [stderr]   Downloaded cranelift-codegen-shared v0.76.0
[INFO] [stderr]   Downloaded cranelift-entity v0.76.0
[INFO] [stderr]   Downloaded cranelift-bforest v0.76.0
[INFO] [stderr]   Downloaded wasmparser v0.79.0
[INFO] [stderr]   Downloaded wast v36.0.0
[INFO] [stderr]   Downloaded cranelift-codegen-meta v0.76.0
[INFO] [stderr]   Downloaded cranelift-codegen v0.76.0
[INFO] [stderr]   Downloaded capstone v0.9.0
[INFO] [stderr]   Downloaded iter-enum v1.0.1
[INFO] [stderr]   Downloaded capstone-sys v0.13.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 347674a1ecbc1ec849885201d6c83ffd03d9a55f44eb3e4c0e8ecb8101661e31
[INFO] running `Command { std: "docker" "start" "-a" "347674a1ecbc1ec849885201d6c83ffd03d9a55f44eb3e4c0e8ecb8101661e31", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "347674a1ecbc1ec849885201d6c83ffd03d9a55f44eb3e4c0e8ecb8101661e31", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "347674a1ecbc1ec849885201d6c83ffd03d9a55f44eb3e4c0e8ecb8101661e31", kill_on_drop: false }`
[INFO] [stdout] 347674a1ecbc1ec849885201d6c83ffd03d9a55f44eb3e4c0e8ecb8101661e31
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f2a9a6cf9769dc3eb13a897ca9aeacf1846bc5e313312a2606f7e927a1a29401
[INFO] running `Command { std: "docker" "start" "-a" "f2a9a6cf9769dc3eb13a897ca9aeacf1846bc5e313312a2606f7e927a1a29401", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]    Compiling libc v0.2.98
[INFO] [stderr]    Compiling cranelift-entity v0.76.0
[INFO] [stderr]    Compiling cranelift-codegen-shared v0.76.0
[INFO] [stderr]    Compiling target-lexicon v0.12.1
[INFO] [stderr]    Compiling rustc-hash v1.1.0
[INFO] [stderr]    Compiling convert_case v0.4.0
[INFO] [stderr]    Compiling wasmparser v0.79.0
[INFO] [stderr]    Compiling arrayvec v0.5.2
[INFO] [stderr]    Compiling more-asserts v0.2.1
[INFO] [stderr]    Compiling capstone-sys v0.13.0
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling gimli v0.25.0
[INFO] [stderr]    Compiling cranelift-codegen-meta v0.76.0
[INFO] [stderr]    Compiling cranelift-bforest v0.76.0
[INFO] [stderr]    Compiling regalloc v0.0.31
[INFO] [stderr]    Compiling memmap2 v0.2.3
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]    Compiling derive_utils v0.11.2
[INFO] [stderr]    Compiling thiserror-impl v1.0.26
[INFO] [stderr]    Compiling dynasm v1.1.0
[INFO] [stderr]    Compiling derive_more v0.99.16
[INFO] [stderr]    Compiling iter-enum v1.0.1
[INFO] [stderr]    Compiling cranelift-codegen v0.76.0
[INFO] [stderr]    Compiling thiserror v1.0.26
[INFO] [stderr]    Compiling dynasmrt v1.1.0
[INFO] [stderr]    Compiling capstone v0.9.0
[INFO] [stderr]    Compiling lightbeam v0.29.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1m 06s
[INFO] running `Command { std: "docker" "inspect" "f2a9a6cf9769dc3eb13a897ca9aeacf1846bc5e313312a2606f7e927a1a29401", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f2a9a6cf9769dc3eb13a897ca9aeacf1846bc5e313312a2606f7e927a1a29401", kill_on_drop: false }`
[INFO] [stdout] f2a9a6cf9769dc3eb13a897ca9aeacf1846bc5e313312a2606f7e927a1a29401
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/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" "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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+1.55.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f144647b4b3b53262d018f348e7026438d82cef8e7075a7a02a897cf0cd04a2a
[INFO] running `Command { std: "docker" "start" "-a" "f144647b4b3b53262d018f348e7026438d82cef8e7075a7a02a897cf0cd04a2a", kill_on_drop: false }`
[INFO] [stderr]    Compiling anyhow v1.0.42
[INFO] [stderr]    Compiling leb128 v0.2.4
[INFO] [stderr]    Compiling getrandom v0.2.3
[INFO] [stderr]    Compiling regalloc v0.0.31
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]    Compiling rand_core v0.6.3
[INFO] [stderr]    Compiling wast v36.0.0
[INFO] [stderr]    Compiling rand v0.8.4
[INFO] [stderr]    Compiling env_logger v0.8.4
[INFO] [stderr]    Compiling quickcheck v1.0.3
[INFO] [stderr]    Compiling cranelift-codegen v0.76.0
[INFO] [stderr]    Compiling wat v1.0.38
[INFO] [stderr]    Compiling lightbeam v0.29.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:19
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![cfg_attr(test, feature(test))]
[INFO] [stdout]   |                   ^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `lightbeam` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "f144647b4b3b53262d018f348e7026438d82cef8e7075a7a02a897cf0cd04a2a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f144647b4b3b53262d018f348e7026438d82cef8e7075a7a02a897cf0cd04a2a", kill_on_drop: false }`
[INFO] [stdout] f144647b4b3b53262d018f348e7026438d82cef8e7075a7a02a897cf0cd04a2a