[INFO] crate algs4 0.7.0 is already in cache
[INFO] testing algs4-0.7.0 against 1.38.0 for beta-1.39-1
[INFO] extracting crate algs4 0.7.0 into work/builds/worker-5/source
[INFO] validating manifest of crates.io crate algs4 0.7.0 on toolchain 1.38.0
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking crates.io crate algs4 0.7.0
[INFO] finished tweaking crates.io crate algs4 0.7.0
[INFO] tweaked toml for crates.io crate algs4 0.7.0 written to work/builds/worker-5/source/Cargo.toml
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/big/crater/work/cargo-home/bin/cargo" "+1.38.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-5/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-5/source:/opt/rustwide/workdir:ro,Z" "-v" "/big/crater/work/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/big/crater/work/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "MAP_USER_ID=1000" "-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" "+1.38.0" "build" "--frozen"`
[INFO] [stdout] 463cef482ad1e2d87feeaed8c0fa6321cbbb02479e57ce38f4569fdbbe4acdeb
[INFO] running `"docker" "start" "-a" "463cef482ad1e2d87feeaed8c0fa6321cbbb02479e57ce38f4569fdbbe4acdeb"`
[INFO] [stderr] warning: dependency (sdl2) specified without providing a local path, Git repository, or version to use. This will be considered an error in future versions
[INFO] [stderr] warning: dependency (sdl2_gfx) specified without providing a local path, Git repository, or version to use. This will be considered an error in future versions
[INFO] [stderr] warning: unused manifest key: dev-dependencies.sdl2.sdl2
[INFO] [stderr] warning: unused manifest key: dev-dependencies.sdl2_gfx.sdl2_gfx
[INFO] [stderr]    Compiling adivon v0.2.6
[INFO] [stderr]    Compiling mtl v0.1.5
[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/adivon-0.2.6/src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(associated_type_defaults, plugin)]
[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/mtl-0.1.5/src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(unboxed_closures, fixed_size_array)]
[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 `adivon`.
[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 `mtl`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "463cef482ad1e2d87feeaed8c0fa6321cbbb02479e57ce38f4569fdbbe4acdeb"`
[INFO] running `"docker" "rm" "-f" "463cef482ad1e2d87feeaed8c0fa6321cbbb02479e57ce38f4569fdbbe4acdeb"`
[INFO] [stdout] 463cef482ad1e2d87feeaed8c0fa6321cbbb02479e57ce38f4569fdbbe4acdeb