[INFO] fetching crate slabmalloc 0.11.0...
[INFO] checking slabmalloc-0.11.0 against 1.95.0 for pr-155915
[INFO] extracting crate slabmalloc 0.11.0 into /workspace/builds/worker-3-tc1/source
[INFO] started tweaking crates.io crate slabmalloc 0.11.0
[INFO] finished tweaking crates.io crate slabmalloc 0.11.0
[INFO] tweaked toml for crates.io crate slabmalloc 0.11.0 written to /workspace/builds/worker-3-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate slabmalloc 0.11.0 on toolchain 1.95.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.95.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate crates.io crate slabmalloc 0.11.0 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" "+1.95.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded scopeguard v1.1.0
[INFO] [stderr]   Downloaded wasi v0.10.2+wasi-snapshot-preview1
[INFO] [stderr]   Downloaded lock_api v0.4.4
[INFO] [stderr]   Downloaded getrandom v0.2.3
[INFO] [stderr]   Downloaded rand_hc v0.3.0
[INFO] [stderr]   Downloaded spin v0.9.0
[INFO] [stderr]   Downloaded atty v0.2.14
[INFO] [stderr]   Downloaded winapi-util v0.1.5
[INFO] [stderr]   Downloaded hermit-abi v0.1.18
[INFO] [stderr]   Downloaded rand_core v0.6.2
[INFO] [stderr]   Downloaded rand_chacha v0.3.0
[INFO] [stderr]   Downloaded humantime v2.1.0
[INFO] [stderr]   Downloaded termcolor v1.1.2
[INFO] [stderr]   Downloaded ppv-lite86 v0.2.10
[INFO] [stderr]   Downloaded env_logger v0.9.0
[INFO] [stderr]   Downloaded log v0.4.14
[INFO] [stderr]   Downloaded memchr v2.4.0
[INFO] [stderr]   Downloaded rand v0.8.3
[INFO] [stderr]   Downloaded aho-corasick v0.7.18
[INFO] [stderr]   Downloaded regex v1.5.4
[INFO] [stderr]   Downloaded regex-syntax v0.6.25
[INFO] [stderr]   Downloaded libc v0.2.95
[INFO] [stderr]   Downloaded winapi v0.3.9
[INFO] [stderr]   Downloaded winapi-x86_64-pc-windows-gnu v0.4.0
[INFO] [stderr]   Downloaded winapi-i686-pc-windows-gnu v0.4.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 324d06aded1a1a3ef54d2870cf641211f347f6c689bf935ef64da8e8ad68bb88
[INFO] running `Command { std: "docker" "start" "-a" "324d06aded1a1a3ef54d2870cf641211f347f6c689bf935ef64da8e8ad68bb88", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "324d06aded1a1a3ef54d2870cf641211f347f6c689bf935ef64da8e8ad68bb88", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "324d06aded1a1a3ef54d2870cf641211f347f6c689bf935ef64da8e8ad68bb88", kill_on_drop: false }`
[INFO] [stdout] 324d06aded1a1a3ef54d2870cf641211f347f6c689bf935ef64da8e8ad68bb88
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-3-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=forbid" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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:d429b63d4308055ea97f60fb1d3dfca48854a00942f1bd2ad806beaf015945ec" "/opt/rustwide/cargo-home/bin/cargo" "+1.95.0" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 245e93aaa9b07d75290010ae1ecae0d60efc2e514da2e26d7c06ac935877cc3f
[INFO] running `Command { std: "docker" "start" "-a" "245e93aaa9b07d75290010ae1ecae0d60efc2e514da2e26d7c06ac935877cc3f", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.95
[INFO] [stderr]     Checking cfg-if v1.0.0
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling log v0.4.14
[INFO] [stderr]     Checking scopeguard v1.1.0
[INFO] [stderr]     Checking ppv-lite86 v0.2.10
[INFO] [stderr]     Checking regex-syntax v0.6.25
[INFO] [stderr]     Checking humantime v2.1.0
[INFO] [stderr]     Checking termcolor v1.1.2
[INFO] [stderr]     Checking lock_api v0.4.4
[INFO] [stderr]     Checking slabmalloc v0.11.0 (/opt/rustwide/workdir)
[INFO] [stderr]     Checking spin v0.9.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:21:35
[INFO] [stdout]    |
[INFO] [stdout] 21 | #![cfg_attr(feature = "unstable", feature(const_mut_refs))]
[INFO] [stdout]    |                                   ^^^^^^^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]    |
[INFO] [stdout]    = help: the feature `const_mut_refs` has been stable since `1.83.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: the feature `const_mut_refs` has been stable since 1.83.0 and no longer requires an attribute to enable
[INFO] [stdout]   --> src/lib.rs:21:43
[INFO] [stdout]    |
[INFO] [stdout] 21 | #![cfg_attr(feature = "unstable", feature(const_mut_refs))]
[INFO] [stdout]    |                                           ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(stable_features)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `slabmalloc` (lib) due to 1 previous error; 1 warning emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "245e93aaa9b07d75290010ae1ecae0d60efc2e514da2e26d7c06ac935877cc3f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "245e93aaa9b07d75290010ae1ecae0d60efc2e514da2e26d7c06ac935877cc3f", kill_on_drop: false }`
[INFO] [stdout] 245e93aaa9b07d75290010ae1ecae0d60efc2e514da2e26d7c06ac935877cc3f
