[INFO] fetching crate printk 0.3.2...
[INFO] checking printk-0.3.2 against 1.95.0 for pr-155915
[INFO] extracting crate printk 0.3.2 into /workspace/builds/worker-7-tc1/source
[INFO] started tweaking crates.io crate printk 0.3.2
[INFO] finished tweaking crates.io crate printk 0.3.2
[INFO] tweaked toml for crates.io crate printk 0.3.2 written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] validating manifest of crates.io crate printk 0.3.2 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] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.95.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]      Locking 13 packages to latest compatible versions
[INFO] [stderr]       Adding conquer-once v0.3.2 (available: v0.4.0)
[INFO] [stderr]       Adding noto-sans-mono-bitmap v0.2.0 (available: v0.3.2)
[INFO] [stderr]       Adding spinning_top v0.2.5 (available: v0.3.0)
[INFO] [stderr]       Adding x86_64 v0.14.13 (available: v0.15.4)
[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]  Downloading crates ...
[INFO] [stderr]   Downloaded bootloader_api v0.11.15
[INFO] [stderr]   Downloaded conquer-once v0.3.2
[INFO] [stderr]   Downloaded spinning_top v0.2.5
[INFO] [stderr]   Downloaded volatile v0.4.6
[INFO] [stderr]   Downloaded conquer-util v0.3.0
[INFO] [stderr]   Downloaded x86_64 v0.14.13
[INFO] [stderr]   Downloaded noto-sans-mono-bitmap v0.2.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 66054f23794576acee3cd1d43519d065d0483de7547b4440c28636e99e21596d
[INFO] running `Command { std: "docker" "start" "-a" "66054f23794576acee3cd1d43519d065d0483de7547b4440c28636e99e21596d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "66054f23794576acee3cd1d43519d065d0483de7547b4440c28636e99e21596d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "66054f23794576acee3cd1d43519d065d0483de7547b4440c28636e99e21596d", kill_on_drop: false }`
[INFO] [stdout] 66054f23794576acee3cd1d43519d065d0483de7547b4440c28636e99e21596d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-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] 7b7825a4c44bce410f37a6e47c1d627410b81b7e2b4c5f9a879c1fbc07193188
[INFO] running `Command { std: "docker" "start" "-a" "7b7825a4c44bce410f37a6e47c1d627410b81b7e2b4c5f9a879c1fbc07193188", kill_on_drop: false }`
[INFO] [stderr]    Compiling bootloader_api v0.11.15
[INFO] [stderr]     Checking conquer-util v0.3.0
[INFO] [stderr]     Checking volatile v0.4.6
[INFO] [stderr]     Checking bit_field v0.10.3
[INFO] [stderr]     Checking noto-sans-mono-bitmap v0.2.0
[INFO] [stderr]     Checking spinning_top v0.2.5
[INFO] [stderr]     Checking conquer-once v0.3.2
[INFO] [stderr]     Checking x86_64 v0.14.13
[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/x86_64-0.14.13/src/lib.rs:5:35
[INFO] [stdout]   |
[INFO] [stdout] 5 | #![cfg_attr(feature = "const_fn", feature(const_mut_refs))] // GDT add_entry()
[INFO] [stdout]   |                                   ^^^^^^^^^^^^^^^^^^^^^^^
[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] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `x86_64` (lib) due to 1 previous error
[INFO] running `Command { std: "docker" "inspect" "7b7825a4c44bce410f37a6e47c1d627410b81b7e2b4c5f9a879c1fbc07193188", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "7b7825a4c44bce410f37a6e47c1d627410b81b7e2b4c5f9a879c1fbc07193188", kill_on_drop: false }`
[INFO] [stdout] 7b7825a4c44bce410f37a6e47c1d627410b81b7e2b4c5f9a879c1fbc07193188