[INFO] updating cached repository gf4t47/rust_os
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/gf4t47/rust_os
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/gf4t47/rust_os" "work/ex/beta-1.38-1/sources/1.37.0/gh/gf4t47/rust_os"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/gf4t47/rust_os'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/gf4t47/rust_os" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/gf4t47/rust_os"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/gf4t47/rust_os'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 7bbafe15c5bb6ad747f8ed8ba6caff8f853b3483
[INFO] sha for GitHub repo gf4t47/rust_os: 7bbafe15c5bb6ad747f8ed8ba6caff8f853b3483
[INFO] validating manifest of gf4t47/rust_os on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of gf4t47/rust_os on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing gf4t47/rust_os
[INFO] finished frobbing gf4t47/rust_os
[INFO] frobbed toml for gf4t47/rust_os written to work/ex/beta-1.38-1/sources/1.37.0/gh/gf4t47/rust_os/Cargo.toml
[INFO] started frobbing gf4t47/rust_os
[INFO] finished frobbing gf4t47/rust_os
[INFO] frobbed toml for gf4t47/rust_os written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/gf4t47/rust_os/Cargo.toml
[INFO] crate gf4t47/rust_os already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing gf4t47/rust_os against 1.37.0 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-5/1.37.0:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/1.37.0/gh/gf4t47/rust_os:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/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=warn" "-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" "+1.37.0" "build" "--frozen"`
[INFO] [stdout] 12169260f713e352568130f5d8a38771f560594c1adedcfdefb3abd7de69d715
[INFO] running `"docker" "start" "-a" "12169260f713e352568130f5d8a38771f560594c1adedcfdefb3abd7de69d715"`
[INFO] [stderr]    Compiling usize_conversions v0.2.0
[INFO] [stderr]    Compiling cpuio v0.2.0
[INFO] [stderr]    Compiling spin v0.4.9
[INFO] [stderr]    Compiling volatile v0.2.5
[INFO] [stderr]    Compiling lazy_static v1.1.0
[INFO] [stderr]    Compiling bootloader_precompiled v0.2.0
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/usize_conversions-0.2.0/src/lib.rs:6:1
[INFO] [stderr]   |
[INFO] [stderr] 6 | #![feature(i128_type)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/cpuio-0.2.0/src/lib.rs:4:1
[INFO] [stderr]   |
[INFO] [stderr] 4 | #![feature(asm, const_fn, no_std)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: Could not compile `usize_conversions`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error[E0554]: #![feature] may not be used on the stable release channel
[INFO] [stderr]  --> /opt/crater/cargo-home/registry/src/github.com-1ecc6299db9ec823/spin-0.4.9/src/lib.rs:6:35
[INFO] [stderr]   |
[INFO] [stderr] 6 | #![cfg_attr(feature = "const_fn", feature(const_fn))]
[INFO] [stderr]   |                                   ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[INFO] [stderr] error: Could not compile `cpuio`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0554`.
[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" "12169260f713e352568130f5d8a38771f560594c1adedcfdefb3abd7de69d715"`
[INFO] running `"docker" "rm" "-f" "12169260f713e352568130f5d8a38771f560594c1adedcfdefb3abd7de69d715"`
[INFO] [stdout] 12169260f713e352568130f5d8a38771f560594c1adedcfdefb3abd7de69d715