[INFO] fetching crate memdb 1.0.0...
[INFO] testing memdb-1.0.0 against beta-2021-09-08 for beta-1.56-1
[INFO] extracting crate memdb 1.0.0 into /workspace/builds/worker-18/source
[INFO] validating manifest of crates.io crate memdb 1.0.0 on toolchain beta-2021-09-08
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate memdb 1.0.0
[INFO] finished tweaking crates.io crate memdb 1.0.0
[INFO] tweaked toml for crates.io crate memdb 1.0.0 written to /workspace/builds/worker-18/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-09-08" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded futures-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded async-datagram v3.0.0
[INFO] [stderr]   Downloaded runtime-attributes v0.3.0-alpha.6
[INFO] [stderr]   Downloaded futures-timer v0.3.0
[INFO] [stderr]   Downloaded runtime-native v0.3.0-alpha.6
[INFO] [stderr]   Downloaded juliex v0.3.0-alpha.8
[INFO] [stderr]   Downloaded futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded async-ready v3.0.0
[INFO] [stderr]   Downloaded runtime-raw v0.3.0-alpha.5
[INFO] [stderr]   Downloaded runtime v0.3.0-alpha.8
[INFO] [stderr]   Downloaded futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]   Downloaded romio v0.3.0-alpha.10
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 0c279f2bae2fc451d58e1cb7c01e56e404a5692ec7b1f5180672d17ba1c4225b
[INFO] running `Command { std: "docker" "start" "-a" "0c279f2bae2fc451d58e1cb7c01e56e404a5692ec7b1f5180672d17ba1c4225b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "0c279f2bae2fc451d58e1cb7c01e56e404a5692ec7b1f5180672d17ba1c4225b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "0c279f2bae2fc451d58e1cb7c01e56e404a5692ec7b1f5180672d17ba1c4225b", kill_on_drop: false }`
[INFO] [stdout] 0c279f2bae2fc451d58e1cb7c01e56e404a5692ec7b1f5180672d17ba1c4225b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-18/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:a89201d6b5b9fd45c15d5952ece0a0129e7e80cb26ec023fd59cf09bc26f1604" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-09-08" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ac44fa86251e188375e52a988862268d42ac122cf9929aa9aaec9a951824d1b3
[INFO] running `Command { std: "docker" "start" "-a" "ac44fa86251e188375e52a988862268d42ac122cf9929aa9aaec9a951824d1b3", kill_on_drop: false }`
[INFO] [stderr]    Compiling semver-parser v0.7.0
[INFO] [stderr]    Compiling maybe-uninit v2.0.0
[INFO] [stderr]    Compiling libc v0.2.101
[INFO] [stderr]    Compiling rand_core v0.4.2
[INFO] [stderr]    Compiling stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling scopeguard v0.3.3
[INFO] [stderr]    Compiling owning_ref v0.4.1
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling semver v0.9.0
[INFO] [stderr]    Compiling lock_api v0.1.5
[INFO] [stderr]    Compiling rustc_version v0.2.3
[INFO] [stderr]    Compiling smallvec v0.6.14
[INFO] [stderr]    Compiling parking_lot_core v0.3.1
[INFO] [stderr]    Compiling rand v0.5.6
[INFO] [stderr]    Compiling parking_lot v0.6.4
[INFO] [stderr]    Compiling memdb v1.0.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(async_await)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `async_await` has been stable since 1.39.0 and no longer requires an attribute to enable
[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 `memdb` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "ac44fa86251e188375e52a988862268d42ac122cf9929aa9aaec9a951824d1b3", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ac44fa86251e188375e52a988862268d42ac122cf9929aa9aaec9a951824d1b3", kill_on_drop: false }`
[INFO] [stdout] ac44fa86251e188375e52a988862268d42ac122cf9929aa9aaec9a951824d1b3