[INFO] fetching crate heph-rt 0.4.1...
[INFO] testing heph-rt-0.4.1 against 1.90.0 for beta-1.91-3
[INFO] extracting crate heph-rt 0.4.1 into /workspace/builds/worker-2-tc1/source
[INFO] started tweaking crates.io crate heph-rt 0.4.1
[INFO] finished tweaking crates.io crate heph-rt 0.4.1
[INFO] tweaked toml for crates.io crate heph-rt 0.4.1 written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate heph-rt 0.4.1 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 heph-rt 0.4.1 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]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded sval v1.0.0-alpha.5
[INFO] [stderr]   Downloaded backtrace v0.3.66
[INFO] [stderr]   Downloaded heph-inbox v0.2.3
[INFO] [stderr]   Downloaded getrandom v0.2.7
[INFO] [stderr]   Downloaded heph v0.4.0
[INFO] [stderr]   Downloaded miniz_oxide v0.5.4
[INFO] [stderr]   Downloaded mio v0.8.4
[INFO] [stderr]   Downloaded proc-macro2 v1.0.46
[INFO] [stderr]   Downloaded mio-signals v0.2.0
[INFO] [stderr]   Downloaded ctor v0.1.23
[INFO] [stderr]   Downloaded std-logger v0.4.4
[INFO] [stderr]   Downloaded log-panics v2.1.0
[INFO] [stderr]   Downloaded value-bag v1.0.0-alpha.9
[INFO] [stderr]   Downloaded object v0.29.0
[INFO] [stderr]   Downloaded syn v1.0.102
[INFO] [stderr]   Downloaded gimli v0.26.2
[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] 99a209874fb05bb77a841e951de07945757238d6d02947654dc1d57a8b229c95
[INFO] running `Command { std: "docker" "start" "-a" "99a209874fb05bb77a841e951de07945757238d6d02947654dc1d57a8b229c95", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "99a209874fb05bb77a841e951de07945757238d6d02947654dc1d57a8b229c95", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "99a209874fb05bb77a841e951de07945757238d6d02947654dc1d57a8b229c95", kill_on_drop: false }`
[INFO] [stdout] 99a209874fb05bb77a841e951de07945757238d6d02947654dc1d57a8b229c95
[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] 3f9f0f9e65c6bdcca5d469405218d6e9918028520e56f3561ac4e0d2684c1944
[INFO] running `Command { std: "docker" "start" "-a" "3f9f0f9e65c6bdcca5d469405218d6e9918028520e56f3561ac4e0d2684c1944", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v1.0.46
[INFO] [stderr]    Compiling syn v1.0.102
[INFO] [stderr]    Compiling log v0.4.17
[INFO] [stderr]    Compiling sval v1.0.0-alpha.5
[INFO] [stderr]    Compiling libc v0.2.135
[INFO] [stderr]    Compiling crossbeam-utils v0.8.12
[INFO] [stderr]    Compiling heph-inbox v0.2.3
[INFO] [stderr]    Compiling value-bag v1.0.0-alpha.9
[INFO] [stderr]    Compiling quote v1.0.21
[INFO] [stderr]    Compiling socket2 v0.4.7
[INFO] [stderr]    Compiling crossbeam-channel v0.5.6
[INFO] [stderr]    Compiling ctor v0.1.23
[INFO] [stderr]    Compiling mio v0.8.4
[INFO] [stderr]    Compiling heph v0.4.0
[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/heph-0.4.0/src/lib.rs:66:1
[INFO] [stdout]    |
[INFO] [stdout] 66 | #![feature(const_option, doc_auto_cfg, doc_cfg_hide, never_type)]
[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 `heph` (lib) due to 1 previous error
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "3f9f0f9e65c6bdcca5d469405218d6e9918028520e56f3561ac4e0d2684c1944", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3f9f0f9e65c6bdcca5d469405218d6e9918028520e56f3561ac4e0d2684c1944", kill_on_drop: false }`
[INFO] [stdout] 3f9f0f9e65c6bdcca5d469405218d6e9918028520e56f3561ac4e0d2684c1944