[INFO] fetching crate overflower_support 0.1.5...
[INFO] testing overflower_support-0.1.5 against beta-2021-08-01 for beta-1.55-1
[INFO] extracting crate overflower_support 0.1.5 into /workspace/builds/worker-7/source
[INFO] validating manifest of crates.io crate overflower_support 0.1.5 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate overflower_support 0.1.5
[INFO] finished tweaking crates.io crate overflower_support 0.1.5
[INFO] tweaked toml for crates.io crate overflower_support 0.1.5 written to /workspace/builds/worker-7/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded env_logger v0.3.5
[INFO] [stderr]   Downloaded thread_local v0.2.7
[INFO] [stderr]   Downloaded memchr v0.1.11
[INFO] [stderr]   Downloaded regex-syntax v0.3.9
[INFO] [stderr]   Downloaded thread-id v2.0.0
[INFO] [stderr]   Downloaded quickcheck v0.2.27
[INFO] [stderr]   Downloaded aho-corasick v0.5.3
[INFO] [stderr]   Downloaded regex v0.1.80
[INFO] [stderr]   Downloaded utf8-ranges v0.1.3
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 74bf699580a314c153c2fa168738926e327133aaf34c23e3ad845a83918bfda6
[INFO] running `Command { std: "docker" "start" "-a" "74bf699580a314c153c2fa168738926e327133aaf34c23e3ad845a83918bfda6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "74bf699580a314c153c2fa168738926e327133aaf34c23e3ad845a83918bfda6", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "74bf699580a314c153c2fa168738926e327133aaf34c23e3ad845a83918bfda6", kill_on_drop: false }`
[INFO] [stdout] 74bf699580a314c153c2fa168738926e327133aaf34c23e3ad845a83918bfda6
[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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 740a35e10f2d4532ebc1b65bbc85da75669f1047db963237ac403b6bf67e17d4
[INFO] running `Command { std: "docker" "start" "-a" "740a35e10f2d4532ebc1b65bbc85da75669f1047db963237ac403b6bf67e17d4", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling overflower_support v0.1.5 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]   --> src/lib.rs:14:1
[INFO] [stdout]    |
[INFO] [stdout] 14 | #![feature(specialization)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `specialization` is incomplete and may not be safe to use and/or cause compiler crashes
[INFO] [stdout]   --> src/lib.rs:14:12
[INFO] [stdout]    |
[INFO] [stdout] 14 | #![feature(specialization)]
[INFO] [stdout]    |            ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout]    = note: see issue #31844 <https://github.com/rust-lang/rust/issues/31844> for more information
[INFO] [stdout]    = help: consider using `min_specialization` instead, which is more stable and complete
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 1 warning emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `overflower_support` due to 2 previous errors; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "740a35e10f2d4532ebc1b65bbc85da75669f1047db963237ac403b6bf67e17d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "740a35e10f2d4532ebc1b65bbc85da75669f1047db963237ac403b6bf67e17d4", kill_on_drop: false }`
[INFO] [stdout] 740a35e10f2d4532ebc1b65bbc85da75669f1047db963237ac403b6bf67e17d4
