[INFO] updating cached repository https://github.com/starfleetcadet75/RustOS
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] a2b2c1afadcf00e2e1d8994cc953a55622456b07
[INFO] testing starfleetcadet75/RustOS against 1.44.0 for beta-1.45-1
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fstarfleetcadet75%2FRustOS" "/workspace/builds/worker-5/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-5/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/starfleetcadet75/RustOS on toolchain 1.44.0
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/starfleetcadet75/RustOS
[INFO] finished tweaking git repo https://github.com/starfleetcadet75/RustOS
[INFO] tweaked toml for git repo https://github.com/starfleetcadet75/RustOS written to /workspace/builds/worker-5/source/Cargo.toml
[INFO] crate git repo https://github.com/starfleetcadet75/RustOS already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+1.44.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-5/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env" "/opt/rustwide/cargo-home/bin/cargo" "+1.44.0" "build" "--frozen"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 97adca4b26a131fd4b105c18c191f625baa4e028c97a96a4aa626bbbda1d1b3a
[INFO] running `"docker" "start" "-a" "97adca4b26a131fd4b105c18c191f625baa4e028c97a96a4aa626bbbda1d1b3a"`
[INFO] [stderr] sudo: setrlimit(RLIMIT_CORE): Operation not permitted
[INFO] [stderr]    Compiling volatile v0.1.0
[INFO] [stderr]    Compiling rlibc v1.0.0
[INFO] [stderr]    Compiling spin v0.4.5
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/spin-0.4.5/src/lib.rs:6:30
[INFO] [stderr]   |
[INFO] [stderr] 6 | #![cfg_attr(feature = "asm", feature(asm))]
[INFO] [stderr]   |                              ^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/spin-0.4.5/src/lib.rs:7:42
[INFO] [stderr]   |
[INFO] [stderr] 7 | #![cfg_attr(feature = "core_intrinsics", feature(core_intrinsics))]
[INFO] [stderr]   |                                          ^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/spin-0.4.5/src/lib.rs:8:35
[INFO] [stderr]   |
[INFO] [stderr] 8 | #![cfg_attr(feature = "const_fn", feature(const_fn))]
[INFO] [stderr]   |                                   ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 3 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: could not compile `spin`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "97adca4b26a131fd4b105c18c191f625baa4e028c97a96a4aa626bbbda1d1b3a"`
[INFO] running `"docker" "rm" "-f" "97adca4b26a131fd4b105c18c191f625baa4e028c97a96a4aa626bbbda1d1b3a"`
[INFO] [stdout] 97adca4b26a131fd4b105c18c191f625baa4e028c97a96a4aa626bbbda1d1b3a