[INFO] fetching crate mcai_models 0.0.1...
[INFO] testing mcai_models-0.0.1 against 1.54.0 for beta-1.55-1
[INFO] extracting crate mcai_models 0.0.1 into /workspace/builds/worker-4/source
[INFO] validating manifest of crates.io crate mcai_models 0.0.1 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mcai_models 0.0.1
[INFO] finished tweaking crates.io crate mcai_models 0.0.1
[INFO] tweaked toml for crates.io crate mcai_models 0.0.1 written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate crates.io crate mcai_models 0.0.1 already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded dyn-clone v1.0.3
[INFO] [stderr]   Downloaded schemars v0.8.0
[INFO] [stderr]   Downloaded schemars_derive v0.8.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8943d4874cba329f494649f29cb6b2a26f9a7241ca7db1a544ebb28343673004
[INFO] running `Command { std: "docker" "start" "-a" "8943d4874cba329f494649f29cb6b2a26f9a7241ca7db1a544ebb28343673004", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8943d4874cba329f494649f29cb6b2a26f9a7241ca7db1a544ebb28343673004", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8943d4874cba329f494649f29cb6b2a26f9a7241ca7db1a544ebb28343673004", kill_on_drop: false }`
[INFO] [stdout] 8943d4874cba329f494649f29cb6b2a26f9a7241ca7db1a544ebb28343673004
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 0d5d628e787632edcf0c2a38def6bf47ec177d40f9af5fe11826041da4828323
[INFO] running `Command { std: "docker" "start" "-a" "0d5d628e787632edcf0c2a38def6bf47ec177d40f9af5fe11826041da4828323", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling syn v1.0.48
[INFO] [stderr]    Compiling serde_derive v1.0.117
[INFO] [stderr]    Compiling serde v1.0.117
[INFO] [stderr]    Compiling itoa v0.4.6
[INFO] [stderr]    Compiling schemars v0.8.0
[INFO] [stderr]    Compiling regex-syntax v0.6.20
[INFO] [stderr]    Compiling dyn-clone v1.0.3
[INFO] [stderr]    Compiling aho-corasick v0.7.14
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stderr]    Compiling regex v1.4.1
[INFO] [stderr]    Compiling serde_derive_internals v0.25.0
[INFO] [stderr]    Compiling schemars_derive v0.8.0
[INFO] [stderr]    Compiling serde_json v1.0.59
[INFO] [stderr]    Compiling mcai_models v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/bin/mcai-model.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(result_flattening)]
[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 `mcai_models`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "0d5d628e787632edcf0c2a38def6bf47ec177d40f9af5fe11826041da4828323", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0d5d628e787632edcf0c2a38def6bf47ec177d40f9af5fe11826041da4828323", kill_on_drop: false }`
[INFO] [stdout] 0d5d628e787632edcf0c2a38def6bf47ec177d40f9af5fe11826041da4828323
