[INFO] fetching crate rustc-ap-serialize 662.0.0...
[INFO] testing rustc-ap-serialize-662.0.0 against 1.90.0 for beta-1.91-3
[INFO] extracting crate rustc-ap-serialize 662.0.0 into /workspace/builds/worker-2-tc1/source
[INFO] started tweaking crates.io crate rustc-ap-serialize 662.0.0
[INFO] finished tweaking crates.io crate rustc-ap-serialize 662.0.0
[INFO] tweaked toml for crates.io crate rustc-ap-serialize 662.0.0 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate rustc-ap-serialize 662.0.0 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]      Locking 4 packages to latest compatible versions
[INFO] [stderr]       Adding indexmap v1.9.3 (available: v2.11.4)
[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]     Blocking waiting for file lock on package cache
[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] af6fc3039d42102545c353e29df25c498ee170067df8e40380cace74cdfe0465
[INFO] running `Command { std: "docker" "start" "-a" "af6fc3039d42102545c353e29df25c498ee170067df8e40380cace74cdfe0465", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "af6fc3039d42102545c353e29df25c498ee170067df8e40380cace74cdfe0465", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "af6fc3039d42102545c353e29df25c498ee170067df8e40380cace74cdfe0465", kill_on_drop: false }`
[INFO] [stdout] af6fc3039d42102545c353e29df25c498ee170067df8e40380cace74cdfe0465
[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] 47c1f06db2329a1dc563c07b04aa61a02a471acad2795ad220366d35061be0fd
[INFO] running `Command { std: "docker" "start" "-a" "47c1f06db2329a1dc563c07b04aa61a02a471acad2795ad220366d35061be0fd", kill_on_drop: false }`
[INFO] [stderr]    Compiling indexmap v1.9.3
[INFO] [stderr]    Compiling smallvec v1.15.1
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/smallvec-1.15.1/src/lib.rs:96:37
[INFO] [stdout]    |
[INFO] [stdout] 96 | #![cfg_attr(feature = "may_dangle", feature(dropck_eyepatch))]
[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 `smallvec` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "47c1f06db2329a1dc563c07b04aa61a02a471acad2795ad220366d35061be0fd", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "47c1f06db2329a1dc563c07b04aa61a02a471acad2795ad220366d35061be0fd", kill_on_drop: false }`
[INFO] [stdout] 47c1f06db2329a1dc563c07b04aa61a02a471acad2795ad220366d35061be0fd