[INFO] fetching crate rustc-ap-rustc_index 683.0.0...
[INFO] testing rustc-ap-rustc_index-683.0.0 against 1.47.0 for beta-1.48-1
[INFO] extracting crate rustc-ap-rustc_index 683.0.0 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate rustc-ap-rustc_index 683.0.0 on toolchain 1.47.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rustc-ap-rustc_index 683.0.0
[INFO] finished tweaking crates.io crate rustc-ap-rustc_index 683.0.0
[INFO] tweaked toml for crates.io crate rustc-ap-rustc_index 683.0.0 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.47.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0a809bbcd5a9a9c5f0bf9ad849420e427fd7596a4886602d61f74c5bf22f807e
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "0a809bbcd5a9a9c5f0bf9ad849420e427fd7596a4886602d61f74c5bf22f807e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0a809bbcd5a9a9c5f0bf9ad849420e427fd7596a4886602d61f74c5bf22f807e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0a809bbcd5a9a9c5f0bf9ad849420e427fd7596a4886602d61f74c5bf22f807e", kill_on_drop: false }`
[INFO] [stdout] 0a809bbcd5a9a9c5f0bf9ad849420e427fd7596a4886602d61f74c5bf22f807e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.47.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d8167d2737de075c1897d29756747cba7d2d394b4fa19131e43b0a6135438c36
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "d8167d2737de075c1897d29756747cba7d2d394b4fa19131e43b0a6135438c36", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.44
[INFO] [stderr]    Compiling smallvec v1.4.2
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/smallvec-1.4.2/src/lib.rs:74:32
[INFO] [stdout]    |
[INFO] [stdout] 74 | #![cfg_attr(feature = "union", feature(untagged_unions))]
[INFO] [stdout]    |                                ^^^^^^^^^^^^^^^^^^^^^^^^
[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/github.com-1ecc6299db9ec823/smallvec-1.4.2/src/lib.rs:77:37
[INFO] [stdout]    |
[INFO] [stdout] 77 | #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))]
[INFO] [stdout]    |                                     ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `smallvec`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "d8167d2737de075c1897d29756747cba7d2d394b4fa19131e43b0a6135438c36", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d8167d2737de075c1897d29756747cba7d2d394b4fa19131e43b0a6135438c36", kill_on_drop: false }`
[INFO] [stdout] d8167d2737de075c1897d29756747cba7d2d394b4fa19131e43b0a6135438c36
