[INFO] cloning repository jbg/os
[INFO] running `"git" "clone" "--bare" "git://github.com/jbg/os.git" "work/cache/sources/gh/jbg/os"`
[INFO] [stderr] Cloning into bare repository 'work/cache/sources/gh/jbg/os'...
[INFO] running `"git" "clone" "work/cache/sources/gh/jbg/os" "work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/gh/jbg/os"`
[INFO] [stderr] Cloning into 'work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/gh/jbg/os'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/jbg/os" "work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/jbg/os"`
[INFO] [stderr] Cloning into 'work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/jbg/os'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] d165783d46dc4c5d76231c3c30b486813ada0048
[INFO] sha for GitHub repo jbg/os: d165783d46dc4c5d76231c3c30b486813ada0048
[INFO] validating manifest of jbg/os on toolchain master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of jbg/os on toolchain try#8f81d0bf6baf07b92f1246696722485c4ca0b049
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing jbg/os
[INFO] finished frobbing jbg/os
[INFO] frobbed toml for jbg/os written to work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/gh/jbg/os/Cargo.toml
[INFO] started frobbing jbg/os
[INFO] finished frobbing jbg/os
[INFO] frobbed toml for jbg/os written to work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/jbg/os/Cargo.toml
[INFO] crate jbg/os already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/ec2-user/crater/work/local/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking jbg/os against try#8f81d0bf6baf07b92f1246696722485c4ca0b049 for pr-62008
[INFO] running `"docker" "create" "-v" "/mnt/big/ec2-user/crater/work/local/target-dirs/pr-62008/worker-5/try#8f81d0bf6baf07b92f1246696722485c4ca0b049:/opt/crater/target:rw,Z" "-v" "/mnt/big/ec2-user/crater/work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/jbg/os:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/ec2-user/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/ec2-user/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+8f81d0bf6baf07b92f1246696722485c4ca0b049-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 849a1b14ab0c5ffd485fdf572ecf27d4318e1f7ae8cecc65b43ae350c7092aa0
[INFO] running `"docker" "start" "-a" "849a1b14ab0c5ffd485fdf572ecf27d4318e1f7ae8cecc65b43ae350c7092aa0"`
[INFO] [stderr]     Checking ux v0.1.2
[INFO] [stderr]     Checking spin v0.4.8
[INFO] [stderr]    Compiling lazy_static v1.1.0
[INFO] [stderr]     Checking multiboot2 v0.7.1
[INFO] [stderr] error[E0635]: unknown feature `const_unsafe_cell_new`
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/spin-0.4.8/src/lib.rs:8:53
[INFO] [stderr]   |
[INFO] [stderr] 8 | #![cfg_attr(feature = "const_fn", feature(const_fn, const_unsafe_cell_new, const_atomic_usize_new))]
[INFO] [stderr]   |                                                     ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0635]: unknown feature `const_atomic_usize_new`
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/spin-0.4.8/src/lib.rs:8:76
[INFO] [stderr]   |
[INFO] [stderr] 8 | #![cfg_attr(feature = "const_fn", feature(const_fn, const_unsafe_cell_new, const_atomic_usize_new))]
[INFO] [stderr]   |                                                                            ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 2 previous errors
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0635`.
[INFO] [stderr] error: Could not compile `spin`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "849a1b14ab0c5ffd485fdf572ecf27d4318e1f7ae8cecc65b43ae350c7092aa0"`
[INFO] running `"docker" "rm" "-f" "849a1b14ab0c5ffd485fdf572ecf27d4318e1f7ae8cecc65b43ae350c7092aa0"`
[INFO] [stdout] 849a1b14ab0c5ffd485fdf572ecf27d4318e1f7ae8cecc65b43ae350c7092aa0