[INFO] fetching crate refs 0.21.0...
[INFO] testing refs-0.21.0 against 1.90.0 for beta-1.91-3
[INFO] extracting crate refs 0.21.0 into /workspace/builds/worker-1-tc1/source
[INFO] started tweaking crates.io crate refs 0.21.0
[INFO] finished tweaking crates.io crate refs 0.21.0
[INFO] tweaked toml for crates.io crate refs 0.21.0 written to /workspace/builds/worker-1-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate refs 0.21.0 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] crate crates.io crate refs 0.21.0 already has a lockfile, it will not be regenerated
[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 sdd v3.0.10
[INFO] [stderr]   Downloaded winapi-util v0.1.10
[INFO] [stderr]   Downloaded wasm-bindgen-test v0.3.50
[INFO] [stderr]   Downloaded wasm-bindgen-test-macro v0.3.50
[INFO] [stderr]   Downloaded minicov v0.3.7
[INFO] [stderr]   Downloaded cc v1.2.34
[INFO] [stderr]   Downloaded scc v2.4.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 37c9ef255857f10bf4cc44b9fb0ef19087f8b94671a84c87b85dd7be53cc084e
[INFO] running `Command { std: "docker" "start" "-a" "37c9ef255857f10bf4cc44b9fb0ef19087f8b94671a84c87b85dd7be53cc084e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "37c9ef255857f10bf4cc44b9fb0ef19087f8b94671a84c87b85dd7be53cc084e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "37c9ef255857f10bf4cc44b9fb0ef19087f8b94671a84c87b85dd7be53cc084e", kill_on_drop: false }`
[INFO] [stdout] 37c9ef255857f10bf4cc44b9fb0ef19087f8b94671a84c87b85dd7be53cc084e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-1-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] 5ae0b6cf5f8481b440eda5f8f89f5da465824ee3e3a1b5821aa81767f6fce8c4
[INFO] running `Command { std: "docker" "start" "-a" "5ae0b6cf5f8481b440eda5f8f89f5da465824ee3e3a1b5821aa81767f6fce8c4", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.101
[INFO] [stderr]    Compiling instant v0.1.13
[INFO] [stderr]    Compiling quote v1.0.40
[INFO] [stderr]    Compiling syn v2.0.106
[INFO] [stderr]    Compiling derive_more-impl v2.0.1
[INFO] [stderr]    Compiling derive_more v2.0.1
[INFO] [stderr]    Compiling refs v0.21.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(specialization)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:4:1
[INFO] [stdout]   |
[INFO] [stdout] 4 | #![feature(unsize)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:5:1
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![feature(coerce_unsized)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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(thread_id_value)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(core_intrinsics)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:8:1
[INFO] [stdout]   |
[INFO] [stdout] 8 | #![feature(const_type_name)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:9:1
[INFO] [stdout]   |
[INFO] [stdout] 9 | #![feature(arbitrary_self_types)]
[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 `refs` (lib) due to 7 previous errors
[INFO] running `Command { std: "docker" "inspect" "5ae0b6cf5f8481b440eda5f8f89f5da465824ee3e3a1b5821aa81767f6fce8c4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5ae0b6cf5f8481b440eda5f8f89f5da465824ee3e3a1b5821aa81767f6fce8c4", kill_on_drop: false }`
[INFO] [stdout] 5ae0b6cf5f8481b440eda5f8f89f5da465824ee3e3a1b5821aa81767f6fce8c4