[INFO] fetching crate mp 0.1.0...
[INFO] testing mp-0.1.0 against 1.45.2 for beta-1.46-1
[INFO] extracting crate mp 0.1.0 into /workspace/builds/worker-1/source
[INFO] validating manifest of crates.io crate mp 0.1.0 on toolchain 1.45.2
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mp 0.1.0
[INFO] finished tweaking crates.io crate mp 0.1.0
[INFO] tweaked toml for crates.io crate mp 0.1.0 written to /workspace/builds/worker-1/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.45.2" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 8bedae3aad525f61ef009fd4d1194ec2460b5220f4f9b94837eb5e1f654d4053
[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" "8bedae3aad525f61ef009fd4d1194ec2460b5220f4f9b94837eb5e1f654d4053", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "8bedae3aad525f61ef009fd4d1194ec2460b5220f4f9b94837eb5e1f654d4053", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "8bedae3aad525f61ef009fd4d1194ec2460b5220f4f9b94837eb5e1f654d4053", kill_on_drop: false }`
[INFO] [stdout] 8bedae3aad525f61ef009fd4d1194ec2460b5220f4f9b94837eb5e1f654d4053
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+1.45.2" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 5d69fbc7bf61ef7f7b13dc2fcd7ec04211c726711cedccd08d7102618d904d68
[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" "5d69fbc7bf61ef7f7b13dc2fcd7ec04211c726711cedccd08d7102618d904d68", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling libc v0.2.74
[INFO] [stderr]    Compiling ucd-util v0.1.8
[INFO] [stderr]    Compiling regex v0.2.11
[INFO] [stderr]    Compiling utf8-ranges v1.0.4
[INFO] [stderr]    Compiling thread_local v0.3.6
[INFO] [stderr]    Compiling regex-syntax v0.5.6
[INFO] [stderr]    Compiling aho-corasick v0.6.10
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling colored v1.9.3
[INFO] [stderr]    Compiling pretty_grammar v0.1.3
[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/pretty_grammar-0.1.3/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] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "5d69fbc7bf61ef7f7b13dc2fcd7ec04211c726711cedccd08d7102618d904d68", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5d69fbc7bf61ef7f7b13dc2fcd7ec04211c726711cedccd08d7102618d904d68", kill_on_drop: false }`
[INFO] [stdout] 5d69fbc7bf61ef7f7b13dc2fcd7ec04211c726711cedccd08d7102618d904d68