[INFO] fetching crate rxrust 1.0.0-alpha.2...
[INFO] testing rxrust-1.0.0-alpha.2 against 1.59.0 for beta-1.60-1
[INFO] extracting crate rxrust 1.0.0-alpha.2 into /workspace/builds/worker-102/source
[INFO] validating manifest of crates.io crate rxrust 1.0.0-alpha.2 on toolchain 1.59.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate rxrust 1.0.0-alpha.2
[INFO] finished tweaking crates.io crate rxrust 1.0.0-alpha.2
[INFO] tweaked toml for crates.io crate rxrust 1.0.0-alpha.2 written to /workspace/builds/worker-102/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.59.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-102/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-102/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] e323a644b6d1d4a9188dc15061f79537577cfc15f5f92e5af0fee49ad054f764
[INFO] running `Command { std: "docker" "start" "-a" "e323a644b6d1d4a9188dc15061f79537577cfc15f5f92e5af0fee49ad054f764", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "e323a644b6d1d4a9188dc15061f79537577cfc15f5f92e5af0fee49ad054f764", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e323a644b6d1d4a9188dc15061f79537577cfc15f5f92e5af0fee49ad054f764", kill_on_drop: false }`
[INFO] [stdout] e323a644b6d1d4a9188dc15061f79537577cfc15f5f92e5af0fee49ad054f764
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-102/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-102/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@sha256:0cd99ca24d8e8c98e67c542213511d985b8778b5bdcbb160e038429496686047" "/opt/rustwide/cargo-home/bin/cargo" "+1.59.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e58dfe3a7273b169bdb04b88761442e176b9bc8bbfd5829a3637270803405ec8
[INFO] running `Command { std: "docker" "start" "-a" "e58dfe3a7273b169bdb04b88761442e176b9bc8bbfd5829a3637270803405ec8", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.86
[INFO] [stderr]    Compiling futures-io v0.3.21
[INFO] [stderr]    Compiling cache-padded v1.2.0
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]    Compiling parking v2.0.0
[INFO] [stderr]    Compiling waker-fn v1.1.0
[INFO] [stderr]    Compiling event-listener v2.5.2
[INFO] [stderr]    Compiling futures-channel v0.3.21
[INFO] [stderr]    Compiling async-task v4.1.0
[INFO] [stderr]    Compiling futures-sink v0.3.21
[INFO] [stderr]    Compiling signal-hook v0.3.13
[INFO] [stderr]    Compiling atomic-waker v1.0.0
[INFO] [stderr]    Compiling smallvec v1.8.0
[INFO] [stderr]    Compiling value-bag v1.0.0-alpha.8
[INFO] [stderr]    Compiling futures-task v0.3.21
[INFO] [stderr]    Compiling futures-util v0.3.21
[INFO] [stderr]    Compiling crossbeam-utils v0.8.7
[INFO] [stderr]    Compiling socket2 v0.4.4
[INFO] [stderr]    Compiling num_cpus v1.13.1
[INFO] [stderr]    Compiling signal-hook-registry v1.4.0
[INFO] [stderr]    Compiling concurrent-queue v1.2.2
[INFO] [stderr]    Compiling futures-lite v1.12.0
[INFO] [stderr]    Compiling async-mutex v1.4.0
[INFO] [stderr]    Compiling async-lock v2.5.0
[INFO] [stderr]    Compiling async-channel v1.6.1
[INFO] [stderr]    Compiling blocking v1.1.0
[INFO] [stderr]    Compiling async-executor v1.4.1
[INFO] [stderr]    Compiling ctor v0.1.21
[INFO] [stderr]    Compiling futures-macro v0.3.21
[INFO] [stderr]    Compiling polling v2.2.0
[INFO] [stderr]    Compiling kv-log-macro v1.0.7
[INFO] [stderr]    Compiling async-io v1.6.0
[INFO] [stderr]    Compiling async-process v1.3.0
[INFO] [stderr]    Compiling async-global-executor v2.0.2
[INFO] [stderr]    Compiling async-std v1.10.0
[INFO] [stderr]    Compiling futures-executor v0.3.21
[INFO] [stderr]    Compiling futures v0.3.21
[INFO] [stderr]    Compiling rxrust v1.0.0-alpha.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(generic_associated_types)]
[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 `rxrust` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "e58dfe3a7273b169bdb04b88761442e176b9bc8bbfd5829a3637270803405ec8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e58dfe3a7273b169bdb04b88761442e176b9bc8bbfd5829a3637270803405ec8", kill_on_drop: false }`
[INFO] [stdout] e58dfe3a7273b169bdb04b88761442e176b9bc8bbfd5829a3637270803405ec8