[INFO] fetching crate uart_16550 0.2.7...
[INFO] checking uart_16550-0.2.7 against master#893fadd11a52aa26fc19c67ee1b79f03d6a1bed3 for pr-77153
[INFO] extracting crate uart_16550 0.2.7 into /workspace/builds/worker-2/source
[INFO] validating manifest of crates.io crate uart_16550 0.2.7 on toolchain 893fadd11a52aa26fc19c67ee1b79f03d6a1bed3
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+893fadd11a52aa26fc19c67ee1b79f03d6a1bed3" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate uart_16550 0.2.7
[INFO] finished tweaking crates.io crate uart_16550 0.2.7
[INFO] tweaked toml for crates.io crate uart_16550 0.2.7 written to /workspace/builds/worker-2/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+893fadd11a52aa26fc19c67ee1b79f03d6a1bed3" "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" "+893fadd11a52aa26fc19c67ee1b79f03d6a1bed3" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+893fadd11a52aa26fc19c67ee1b79f03d6a1bed3" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 4b4520530551c86b2470389d6bf38c9d767d16ad6c295a5fb21ee17fc9a4275e
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "4b4520530551c86b2470389d6bf38c9d767d16ad6c295a5fb21ee17fc9a4275e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "4b4520530551c86b2470389d6bf38c9d767d16ad6c295a5fb21ee17fc9a4275e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4b4520530551c86b2470389d6bf38c9d767d16ad6c295a5fb21ee17fc9a4275e", kill_on_drop: false }`
[INFO] [stdout] 4b4520530551c86b2470389d6bf38c9d767d16ad6c295a5fb21ee17fc9a4275e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2/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" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+893fadd11a52aa26fc19c67ee1b79f03d6a1bed3" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 93492793c820ac6c8c2bde619d260cffa443a683708121a81afad0f33791acee
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "93492793c820ac6c8c2bde619d260cffa443a683708121a81afad0f33791acee", kill_on_drop: false }`
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling x86_64 v0.11.8
[INFO] [stderr]     Checking bit_field v0.9.0
[INFO] [stdout] error[E0723]: mutable references in const fn are unstable
[INFO] [stdout]    --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/x86_64-0.11.8/src/structures/idt.rs:378:31
[INFO] [stdout]     |
[INFO] [stdout] 378 |                 divide_error: Entry::missing(),
[INFO] [stdout]     |                               ^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: see issue #57563 <https://github.com/rust-lang/rust/issues/57563> for more information
[INFO] [stdout]     = help: add `#![feature(const_fn)]` to the crate attributes to enable
[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 E0723`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `x86_64`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "93492793c820ac6c8c2bde619d260cffa443a683708121a81afad0f33791acee", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "93492793c820ac6c8c2bde619d260cffa443a683708121a81afad0f33791acee", kill_on_drop: false }`
[INFO] [stdout] 93492793c820ac6c8c2bde619d260cffa443a683708121a81afad0f33791acee