[INFO] fetching crate monotonic_solver 0.5.0...
[INFO] testing monotonic_solver-0.5.0 against 1.55.0 for beta-1.56-1
[INFO] extracting crate monotonic_solver 0.5.0 into /workspace/builds/worker-73/source
[INFO] validating manifest of crates.io crate monotonic_solver 0.5.0 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 monotonic_solver 0.5.0
[INFO] finished tweaking crates.io crate monotonic_solver 0.5.0
[INFO] tweaked toml for crates.io crate monotonic_solver 0.5.0 written to /workspace/builds/worker-73/source/Cargo.toml
[INFO] crate crates.io crate monotonic_solver 0.5.0 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-73/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-73/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] 1584b0fb26716ae787c1e3c707a27d260f65f430ed6705c6000d8ffaa4fe8fa4
[INFO] running `Command { std: "docker" "start" "-a" "1584b0fb26716ae787c1e3c707a27d260f65f430ed6705c6000d8ffaa4fe8fa4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1584b0fb26716ae787c1e3c707a27d260f65f430ed6705c6000d8ffaa4fe8fa4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1584b0fb26716ae787c1e3c707a27d260f65f430ed6705c6000d8ffaa4fe8fa4", kill_on_drop: false }`
[INFO] [stdout] 1584b0fb26716ae787c1e3c707a27d260f65f430ed6705c6000d8ffaa4fe8fa4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-73/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-73/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] 239898e8a7659be546061deb163fcf6eed692e2c036cd0297df14fce9cae0b8a
[INFO] running `Command { std: "docker" "start" "-a" "239898e8a7659be546061deb163fcf6eed692e2c036cd0297df14fce9cae0b8a", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling monotonic_solver v0.5.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 1.23s
[INFO] running `Command { std: "docker" "inspect" "239898e8a7659be546061deb163fcf6eed692e2c036cd0297df14fce9cae0b8a", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "239898e8a7659be546061deb163fcf6eed692e2c036cd0297df14fce9cae0b8a", kill_on_drop: false }`
[INFO] [stdout] 239898e8a7659be546061deb163fcf6eed692e2c036cd0297df14fce9cae0b8a
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-73/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-73/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] 66186f98ccca54deb3d118883b5ff8f563608dd49a453ff99460283efa99315c
[INFO] running `Command { std: "docker" "start" "-a" "66186f98ccca54deb3d118883b5ff8f563608dd49a453ff99460283efa99315c", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling monotonic_solver v0.5.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> examples/drama.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(box_patterns)]
[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 `monotonic_solver` 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" "66186f98ccca54deb3d118883b5ff8f563608dd49a453ff99460283efa99315c", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "66186f98ccca54deb3d118883b5ff8f563608dd49a453ff99460283efa99315c", kill_on_drop: false }`
[INFO] [stdout] 66186f98ccca54deb3d118883b5ff8f563608dd49a453ff99460283efa99315c