[INFO] fetching crate unmp-link-websocket 0.7.1...
[INFO] testing unmp-link-websocket-0.7.1 against beta-2025-09-21 for beta-1.91-3
[INFO] extracting crate unmp-link-websocket 0.7.1 into /workspace/builds/worker-7-tc2/source
[INFO] started tweaking crates.io crate unmp-link-websocket 0.7.1
[INFO] finished tweaking crates.io crate unmp-link-websocket 0.7.1
[INFO] tweaked toml for crates.io crate unmp-link-websocket 0.7.1 written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] validating manifest of crates.io crate unmp-link-websocket 0.7.1 on toolchain beta-2025-09-21
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "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" "+beta-2025-09-21" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 159 packages to latest compatible versions
[INFO] [stderr]       Adding async-tungstenite v0.13.1 (available: v0.31.0)
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+beta-2025-09-21" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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" "+beta-2025-09-21" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 65f18d92757007d4362b1f3c7205f15e9610c433a6db891945006afe22e75ded
[INFO] running `Command { std: "docker" "start" "-a" "65f18d92757007d4362b1f3c7205f15e9610c433a6db891945006afe22e75ded", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "65f18d92757007d4362b1f3c7205f15e9610c433a6db891945006afe22e75ded", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "65f18d92757007d4362b1f3c7205f15e9610c433a6db891945006afe22e75ded", kill_on_drop: false }`
[INFO] [stdout] 65f18d92757007d4362b1f3c7205f15e9610c433a6db891945006afe22e75ded
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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" "+beta-2025-09-21" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] caa05680cc901cc7d0835c4b8bb3b44063fc3a49fcfea3c50ac062bede1dc240
[INFO] running `Command { std: "docker" "start" "-a" "caa05680cc901cc7d0835c4b8bb3b44063fc3a49fcfea3c50ac062bede1dc240", kill_on_drop: false }`
[INFO] [stderr]    Compiling event-listener v5.4.1
[INFO] [stderr]    Compiling generic-array v0.14.7
[INFO] [stderr]    Compiling getrandom v0.2.16
[INFO] [stderr]    Compiling serde v1.0.228
[INFO] [stderr]    Compiling spin_loop v0.1.1
[INFO] [stderr]    Compiling atomic v0.5.3
[INFO] [stderr]    Compiling idna_adapter v1.2.1
[INFO] [stderr]    Compiling futures-util v0.3.31
[INFO] [stderr]    Compiling async-signal v0.2.13
[INFO] [stderr]    Compiling idna v1.1.0
[INFO] [stderr]    Compiling event-listener-strategy v0.5.4
[INFO] [stderr]    Compiling ach-util v0.1.16
[INFO] [stderr]    Compiling rand_core v0.6.4
[INFO] [stderr]    Compiling async-channel v2.5.0
[INFO] [stderr]    Compiling async-lock v3.4.1
[INFO] [stderr]    Compiling ach-ring v0.1.9
[INFO] [stderr]    Compiling rand_chacha v0.3.1
[INFO] [stderr]    Compiling crc16 v0.4.0
[INFO] [stderr]    Compiling blocking v1.6.2
[INFO] [stderr]    Compiling block-buffer v0.9.0
[INFO] [stderr]    Compiling digest v0.9.0
[INFO] [stderr]    Compiling async-process v2.5.0
[INFO] [stderr]    Compiling sha-1 v0.9.8
[INFO] [stderr]    Compiling rand v0.8.5
[INFO] [stderr]    Compiling async-global-executor v2.4.1
[INFO] [stderr]    Compiling ach-mpmc v0.2.0
[INFO] [stderr]    Compiling input_buffer v0.4.0
[INFO] [stderr]    Compiling spin v0.9.8
[INFO] [stderr]    Compiling url v2.5.7
[INFO] [stderr]    Compiling futures-intrusive v0.4.2
[INFO] [stderr]    Compiling fixed-queue v0.3.11
[INFO] [stderr]    Compiling base64 v0.13.1
[INFO] [stderr]    Compiling async-std v1.13.2
[INFO] [stderr]    Compiling unmp-id v2.0.0
[INFO] [stderr]    Compiling unmp-link v0.7.0
[INFO] [stderr]    Compiling tungstenite v0.13.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/unmp-link-0.7.0/src/lib.rs:6:1
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(const_btree_new)]
[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 `unmp-link` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "caa05680cc901cc7d0835c4b8bb3b44063fc3a49fcfea3c50ac062bede1dc240", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "caa05680cc901cc7d0835c4b8bb3b44063fc3a49fcfea3c50ac062bede1dc240", kill_on_drop: false }`
[INFO] [stdout] caa05680cc901cc7d0835c4b8bb3b44063fc3a49fcfea3c50ac062bede1dc240
