[INFO] fetching crate metron_core 0.0.1...
[INFO] testing metron_core-0.0.1 against 1.91.0 for beta-1.92-2
[INFO] extracting crate metron_core 0.0.1 into /workspace/builds/worker-4-tc1/source
[INFO] started tweaking crates.io crate metron_core 0.0.1
[INFO] finished tweaking crates.io crate metron_core 0.0.1
[INFO] tweaked toml for crates.io crate metron_core 0.0.1 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate metron_core 0.0.1 on toolchain 1.91.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "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" "+1.91.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 2 packages to latest compatible versions
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.91.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 40eadf177d1f2d3a2cf728bbc3354e8f56f24fab154e744e766290b7a21ded4d
[INFO] running `Command { std: "docker" "start" "-a" "40eadf177d1f2d3a2cf728bbc3354e8f56f24fab154e744e766290b7a21ded4d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "40eadf177d1f2d3a2cf728bbc3354e8f56f24fab154e744e766290b7a21ded4d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "40eadf177d1f2d3a2cf728bbc3354e8f56f24fab154e744e766290b7a21ded4d", kill_on_drop: false }`
[INFO] [stdout] 40eadf177d1f2d3a2cf728bbc3354e8f56f24fab154e744e766290b7a21ded4d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+1.91.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 9fd345f6cebcbc665e54c271a04035675d20ca9000890846a1cc062dc096b6d2
[INFO] running `Command { std: "docker" "start" "-a" "9fd345f6cebcbc665e54c271a04035675d20ca9000890846a1cc062dc096b6d2", kill_on_drop: false }`
[INFO] [stderr]    Compiling autocfg v1.5.0
[INFO] [stderr]    Compiling num-traits v0.2.19
[INFO] [stderr]    Compiling metron_core v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(associated_type_bounds)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `associated_type_bounds` has been stable since `1.79.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(once_cell)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `associated_type_bounds` has been stable since 1.79.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(associated_type_bounds)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `once_cell` has been stable since 1.70.0 and no longer requires an attribute to enable
[INFO] [stdout]  --> src/lib.rs:2:12
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(once_cell)]
[INFO] [stdout]   |            ^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `metron_core` (lib) due to 2 previous errors; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "9fd345f6cebcbc665e54c271a04035675d20ca9000890846a1cc062dc096b6d2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "9fd345f6cebcbc665e54c271a04035675d20ca9000890846a1cc062dc096b6d2", kill_on_drop: false }`
[INFO] [stdout] 9fd345f6cebcbc665e54c271a04035675d20ca9000890846a1cc062dc096b6d2