[INFO] fetching crate pretty_grammar 0.1.3...
[INFO] testing pretty_grammar-0.1.3 against 1.47.0 for beta-1.48-1
[INFO] extracting crate pretty_grammar 0.1.3 into /workspace/builds/worker-5/source
[INFO] validating manifest of crates.io crate pretty_grammar 0.1.3 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 pretty_grammar 0.1.3
[INFO] finished tweaking crates.io crate pretty_grammar 0.1.3
[INFO] tweaked toml for crates.io crate pretty_grammar 0.1.3 written to /workspace/builds/worker-5/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-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] f85ca1811e4ed9089a9013a8ad6246bfb3536109dff5382cc73c7f056d85c774
[INFO] running `Command { std: "docker" "start" "-a" "f85ca1811e4ed9089a9013a8ad6246bfb3536109dff5382cc73c7f056d85c774", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f85ca1811e4ed9089a9013a8ad6246bfb3536109dff5382cc73c7f056d85c774", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f85ca1811e4ed9089a9013a8ad6246bfb3536109dff5382cc73c7f056d85c774", kill_on_drop: false }`
[INFO] [stdout] f85ca1811e4ed9089a9013a8ad6246bfb3536109dff5382cc73c7f056d85c774
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 1b39ffcea57d2eca41e8c1d0c2efea6f371470b764aa99fc97fcfeeaa8ea6e90
[INFO] running `Command { std: "docker" "start" "-a" "1b39ffcea57d2eca41e8c1d0c2efea6f371470b764aa99fc97fcfeeaa8ea6e90", kill_on_drop: false }`
[INFO] [stderr]    Compiling pretty_grammar v0.1.3 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:13:1
[INFO] [stdout]    |
[INFO] [stdout] 13 | #![feature(external_doc)]
[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 `pretty_grammar`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "1b39ffcea57d2eca41e8c1d0c2efea6f371470b764aa99fc97fcfeeaa8ea6e90", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1b39ffcea57d2eca41e8c1d0c2efea6f371470b764aa99fc97fcfeeaa8ea6e90", kill_on_drop: false }`
[INFO] [stdout] 1b39ffcea57d2eca41e8c1d0c2efea6f371470b764aa99fc97fcfeeaa8ea6e90
