[INFO] updating cached repository https://github.com/sgkim126/rust-worksheet
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/big/crater/work/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] 84af7adbb0e4415354d46a8795cfcabf6abfe494
[INFO] testing sgkim126/rust-worksheet against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2Fsgkim126%2Frust-worksheet" "work/builds/worker-3/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-3/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/sgkim126/rust-worksheet 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 git repo https://github.com/sgkim126/rust-worksheet
[INFO] finished tweaking git repo https://github.com/sgkim126/rust-worksheet
[INFO] tweaked toml for git repo https://github.com/sgkim126/rust-worksheet written to work/builds/worker-3/source/Cargo.toml
[INFO] crate git repo https://github.com/sgkim126/rust-worksheet already has a lockfile, it will not be regenerated
[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-3/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-3/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] 0a60fb67052b7e8b0a31bef12e58a436d54570f7a5a8b57764e2ce4ca273cb73
[INFO] running `"docker" "start" "-a" "0a60fb67052b7e8b0a31bef12e58a436d54570f7a5a8b57764e2ce4ca273cb73"`
[INFO] [stderr]    Compiling rust-worksheet v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> src/main.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![feature(rustc_private)]
[INFO] [stderr]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated item 'core::str::<impl str>::trim_right_matches': superseded by `trim_end_matches`
[INFO] [stderr]   --> src/main.rs:26:52
[INFO] [stderr]    |
[INFO] [stderr] 26 |         .ok().expect("sysroot is not valid UTF-8").trim_right_matches(
[INFO] [stderr]    |                                                    ^^^^^^^^^^^^^^^^^^ help: replace the use of the deprecated item: `trim_end_matches`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(deprecated)]` on by default
[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 `rust-worksheet`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0a60fb67052b7e8b0a31bef12e58a436d54570f7a5a8b57764e2ce4ca273cb73"`
[INFO] running `"docker" "rm" "-f" "0a60fb67052b7e8b0a31bef12e58a436d54570f7a5a8b57764e2ce4ca273cb73"`
[INFO] [stdout] 0a60fb67052b7e8b0a31bef12e58a436d54570f7a5a8b57764e2ce4ca273cb73