[INFO] fetching crate uart_16550 0.2.8...
[INFO] checking uart_16550-0.2.8 against try#894d32a5432c6a6461bb2aac7c3d5f2e87dce83f for pr-77015
[INFO] extracting crate uart_16550 0.2.8 into /workspace/builds/worker-14/source
[INFO] validating manifest of crates.io crate uart_16550 0.2.8 on toolchain 894d32a5432c6a6461bb2aac7c3d5f2e87dce83f
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking crates.io crate uart_16550 0.2.8
[INFO] finished tweaking crates.io crate uart_16550 0.2.8
[INFO] tweaked toml for crates.io crate uart_16550 0.2.8 written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] fbf31d74215e601cd4af6e27062cf77d92b8ff576c98351b0182aa5c26d89022
[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" "fbf31d74215e601cd4af6e27062cf77d92b8ff576c98351b0182aa5c26d89022", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "fbf31d74215e601cd4af6e27062cf77d92b8ff576c98351b0182aa5c26d89022", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fbf31d74215e601cd4af6e27062cf77d92b8ff576c98351b0182aa5c26d89022", kill_on_drop: false }`
[INFO] [stdout] fbf31d74215e601cd4af6e27062cf77d92b8ff576c98351b0182aa5c26d89022
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "+894d32a5432c6a6461bb2aac7c3d5f2e87dce83f" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 05f1763533f1362835ba351c5ed0559f9cb3c58d03881d1f70a718d286fa9d12
[INFO] running `Command { std: "docker" "start" "-a" "05f1763533f1362835ba351c5ed0559f9cb3c58d03881d1f70a718d286fa9d12", kill_on_drop: false }`
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling x86_64 v0.12.2
[INFO] [stderr]     Checking bit_field v0.9.0
[INFO] [stdout] error[E0635]: unknown feature `const_fn_fn_ptr_basics`
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/x86_64-0.12.2/src/lib.rs:7:43
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![cfg_attr(feature = "const_fn", feature(const_fn_fn_ptr_basics))]
[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 E0635`.
[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" "05f1763533f1362835ba351c5ed0559f9cb3c58d03881d1f70a718d286fa9d12", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "05f1763533f1362835ba351c5ed0559f9cb3c58d03881d1f70a718d286fa9d12", kill_on_drop: false }`
[INFO] [stdout] 05f1763533f1362835ba351c5ed0559f9cb3c58d03881d1f70a718d286fa9d12