[INFO] fetching crate tokio-resource-pool 0.5.0-alpha.1...
[INFO] testing tokio-resource-pool-0.5.0-alpha.1 against 1.90.0 for beta-1.91-3
[INFO] extracting crate tokio-resource-pool 0.5.0-alpha.1 into /workspace/builds/worker-0-tc1/source
[INFO] started tweaking crates.io crate tokio-resource-pool 0.5.0-alpha.1
[INFO] finished tweaking crates.io crate tokio-resource-pool 0.5.0-alpha.1
[INFO] tweaked toml for crates.io crate tokio-resource-pool 0.5.0-alpha.1 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate tokio-resource-pool 0.5.0-alpha.1 on toolchain 1.90.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 23 packages to latest compatible versions
[INFO] [stderr]       Adding crossbeam-queue v0.1.2 (available: v0.3.12)
[INFO] [stderr]       Adding tokio v0.2.25 (available: v1.47.1)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.90.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded tokio-sync v0.2.0-alpha.6
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 63c140a01af65ef44e50aa542538a03300fcccd25ea85bc1324c3231960eabc9
[INFO] running `Command { std: "docker" "start" "-a" "63c140a01af65ef44e50aa542538a03300fcccd25ea85bc1324c3231960eabc9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "63c140a01af65ef44e50aa542538a03300fcccd25ea85bc1324c3231960eabc9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "63c140a01af65ef44e50aa542538a03300fcccd25ea85bc1324c3231960eabc9", kill_on_drop: false }`
[INFO] [stdout] 63c140a01af65ef44e50aa542538a03300fcccd25ea85bc1324c3231960eabc9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "RUSTDOCFLAGS=--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:e90291280db7d1fac5b66fc6dad9f9662629e7365a55743daf9bdf73ebc4ea79" "/opt/rustwide/cargo-home/bin/cargo" "+1.90.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e2149594930e4acec9287041fc607b29ee92594869648f0f6209a3143298b8ec
[INFO] running `Command { std: "docker" "start" "-a" "e2149594930e4acec9287041fc607b29ee92594869648f0f6209a3143298b8ec", kill_on_drop: false }`
[INFO] [stderr]    Compiling futures-core-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-sink-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-io-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling crossbeam-utils v0.6.6
[INFO] [stderr]    Compiling futures-channel-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling futures-util-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling crossbeam-queue v0.1.2
[INFO] [stderr]    Compiling futures-executor-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling tokio-sync v0.2.0-alpha.6
[INFO] [stderr]    Compiling futures-preview v0.3.0-alpha.19
[INFO] [stderr]    Compiling tokio-resource-pool v0.5.0-alpha.1 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]    --> src/lib.rs:136:1
[INFO] [stdout]     |
[INFO] [stdout] 136 | #![feature(associated_type_defaults)]
[INFO] [stdout]     | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `tokio-resource-pool` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "e2149594930e4acec9287041fc607b29ee92594869648f0f6209a3143298b8ec", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e2149594930e4acec9287041fc607b29ee92594869648f0f6209a3143298b8ec", kill_on_drop: false }`
[INFO] [stdout] e2149594930e4acec9287041fc607b29ee92594869648f0f6209a3143298b8ec