[INFO] fetching crate unmp-protocol-raw 0.7.1...
[INFO] testing unmp-protocol-raw-0.7.1 against 1.60.0 for beta-1.61-1
[INFO] extracting crate unmp-protocol-raw 0.7.1 into /workspace/builds/worker-27/source
[INFO] validating manifest of crates.io crate unmp-protocol-raw 0.7.1 on toolchain 1.60.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate unmp-protocol-raw 0.7.1
[INFO] finished tweaking crates.io crate unmp-protocol-raw 0.7.1
[INFO] tweaked toml for crates.io crate unmp-protocol-raw 0.7.1 written to /workspace/builds/worker-27/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.60.0" "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" "+1.60.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded crc16 v0.4.0
[INFO] [stderr]   Downloaded unmp v0.7.3
[INFO] [stderr]   Downloaded task-stream v0.3.3
[INFO] [stderr]   Downloaded unmp-id v2.0.0
[INFO] [stderr]   Downloaded unmp-link v0.7.0
[INFO] [stderr]   Downloaded fixed-queue v0.3.11
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-27/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-27/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1c9f9b602f0f84cfa9395820a5eef174fe71f352b6c5474f3c4dba9eadb208d4
[INFO] running `Command { std: "docker" "start" "-a" "1c9f9b602f0f84cfa9395820a5eef174fe71f352b6c5474f3c4dba9eadb208d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1c9f9b602f0f84cfa9395820a5eef174fe71f352b6c5474f3c4dba9eadb208d4", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1c9f9b602f0f84cfa9395820a5eef174fe71f352b6c5474f3c4dba9eadb208d4", kill_on_drop: false }`
[INFO] [stdout] 1c9f9b602f0f84cfa9395820a5eef174fe71f352b6c5474f3c4dba9eadb208d4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-27/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-27/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:b0c94ce3c1162fcb8e57cac5b65ec2f72eabb1eebea4fcc35e269e823f681646" "/opt/rustwide/cargo-home/bin/cargo" "+1.60.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 15d4d3fe2a814f1e07e5710e09c5e92822bc0aec13c3decebc97bb741bba7442
[INFO] running `Command { std: "docker" "start" "-a" "15d4d3fe2a814f1e07e5710e09c5e92822bc0aec13c3decebc97bb741bba7442", kill_on_drop: false }`
[INFO] [stderr]    Compiling futures-core v0.3.21
[INFO] [stderr]    Compiling byteorder v1.4.3
[INFO] [stderr]    Compiling heapless v0.7.10
[INFO] [stderr]    Compiling futures-task v0.3.21
[INFO] [stderr]    Compiling crc16 v0.4.0
[INFO] [stderr]    Compiling stable_deref_trait v1.2.0
[INFO] [stderr]    Compiling futures-util v0.3.21
[INFO] [stderr]    Compiling async-task v4.2.0
[INFO] [stderr]    Compiling fixed-queue v0.3.11
[INFO] [stderr]    Compiling unmp-id v2.0.0
[INFO] [stderr]    Compiling spin v0.9.2
[INFO] [stderr]    Compiling getrandom v0.2.6
[INFO] [stderr]    Compiling hash32 v0.2.1
[INFO] [stderr]    Compiling futures-intrusive v0.4.0
[INFO] [stderr]    Compiling task-stream v0.3.3
[INFO] [stderr]    Compiling unmp-link v0.7.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/unmp-link-0.7.0/src/lib.rs:6:12
[INFO] [stdout]   |
[INFO] [stdout] 6 | #![feature(const_btree_new)]
[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 `unmp-link` due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "15d4d3fe2a814f1e07e5710e09c5e92822bc0aec13c3decebc97bb741bba7442", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "15d4d3fe2a814f1e07e5710e09c5e92822bc0aec13c3decebc97bb741bba7442", kill_on_drop: false }`
[INFO] [stdout] 15d4d3fe2a814f1e07e5710e09c5e92822bc0aec13c3decebc97bb741bba7442