[INFO] fetching crate metron 0.0.1...
[INFO] testing metron-0.0.1 against 1.90.0 for beta-1.91-3
[INFO] extracting crate metron 0.0.1 into /workspace/builds/worker-7-tc1/source
[INFO] started tweaking crates.io crate metron 0.0.1
[INFO] finished tweaking crates.io crate metron 0.0.1
[INFO] tweaked toml for crates.io crate metron 0.0.1 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate metron 0.0.1 on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "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" "+1.90.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 66 packages to latest compatible versions
[INFO] [stderr]       Adding criterion v0.3.6 (available: v0.7.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded metron_core v0.0.1
[INFO] [stderr]   Downloaded metron_library v0.0.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e1567b12c3d0426d421397b492fb280c2c461ebedce1a4906818f0a076163e43
[INFO] running `Command { std: "docker" "start" "-a" "e1567b12c3d0426d421397b492fb280c2c461ebedce1a4906818f0a076163e43", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e1567b12c3d0426d421397b492fb280c2c461ebedce1a4906818f0a076163e43", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e1567b12c3d0426d421397b492fb280c2c461ebedce1a4906818f0a076163e43", kill_on_drop: false }`
[INFO] [stdout] e1567b12c3d0426d421397b492fb280c2c461ebedce1a4906818f0a076163e43
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 993f8fde6af3038590f7776ab44d77040c2f5105531341e4dec6837bd5c8567b
[INFO] running `Command { std: "docker" "start" "-a" "993f8fde6af3038590f7776ab44d77040c2f5105531341e4dec6837bd5c8567b", kill_on_drop: false }`
[INFO] [stderr]    Compiling metron_core v0.0.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/metron_core-0.0.1/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]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/metron_core-0.0.1/src/lib.rs:2:1
[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
[INFO] running `Command { std: "docker" "inspect" "993f8fde6af3038590f7776ab44d77040c2f5105531341e4dec6837bd5c8567b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "993f8fde6af3038590f7776ab44d77040c2f5105531341e4dec6837bd5c8567b", kill_on_drop: false }`
[INFO] [stdout] 993f8fde6af3038590f7776ab44d77040c2f5105531341e4dec6837bd5c8567b