[INFO] fetching crate yarnn 0.1.0...
[INFO] testing yarnn-0.1.0 against 1.90.0 for beta-1.91-3
[INFO] extracting crate yarnn 0.1.0 into /workspace/builds/worker-2-tc1/source
[INFO] started tweaking crates.io crate yarnn 0.1.0
[INFO] finished tweaking crates.io crate yarnn 0.1.0
[INFO] tweaked toml for crates.io crate yarnn 0.1.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate yarnn 0.1.0 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 16 packages to latest compatible versions
[INFO] [stderr]       Adding rand v0.7.3 (available: v0.9.2)
[INFO] [stderr]       Adding rand_distr v0.2.2 (available: v0.5.1)
[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 rand_distr v0.2.2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] fcf0b58b84ee64a783ff57e6f948a8defb00c182a8910ef8fb876f9088da3627
[INFO] running `Command { std: "docker" "start" "-a" "fcf0b58b84ee64a783ff57e6f948a8defb00c182a8910ef8fb876f9088da3627", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fcf0b58b84ee64a783ff57e6f948a8defb00c182a8910ef8fb876f9088da3627", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fcf0b58b84ee64a783ff57e6f948a8defb00c182a8910ef8fb876f9088da3627", kill_on_drop: false }`
[INFO] [stdout] fcf0b58b84ee64a783ff57e6f948a8defb00c182a8910ef8fb876f9088da3627
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 294a87e5e940d54ca53b4f29881d9582f1d4dd67ef863ec8193adbbb6060b968
[INFO] running `Command { std: "docker" "start" "-a" "294a87e5e940d54ca53b4f29881d9582f1d4dd67ef863ec8193adbbb6060b968", kill_on_drop: false }`
[INFO] [stderr]    Compiling getrandom v0.1.16
[INFO] [stderr]    Compiling rand_core v0.5.1
[INFO] [stderr]    Compiling rand_chacha v0.2.2
[INFO] [stderr]    Compiling rand v0.7.3
[INFO] [stderr]    Compiling rand_distr v0.2.2
[INFO] [stderr]    Compiling yarnn v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization, trait_alias)]
[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:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(specialization, trait_alias)]
[INFO] [stdout]   |            ^^^^^^^^^^^^^^
[INFO] [stdout]   |
[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]   = note: `#[warn(incomplete_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `yarnn` (lib) due to 1 previous error; 1 warning emitted
[INFO] running `Command { std: "docker" "inspect" "294a87e5e940d54ca53b4f29881d9582f1d4dd67ef863ec8193adbbb6060b968", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "294a87e5e940d54ca53b4f29881d9582f1d4dd67ef863ec8193adbbb6060b968", kill_on_drop: false }`
[INFO] [stdout] 294a87e5e940d54ca53b4f29881d9582f1d4dd67ef863ec8193adbbb6060b968