[INFO] updating cached repository https://github.com/MSleepyPanda/explain-rs
[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] 10522cf5c80910dfa6a0c1db49360ecef247cf89
[INFO] testing MSleepyPanda/explain-rs against 1.38.0 for beta-1.39-1
[INFO] running `"git" "clone" "work/cache/git-repos/https%3A%2F%2Fgithub.com%2FMSleepyPanda%2Fexplain-rs" "work/builds/worker-11/source"`
[INFO] [stderr] Cloning into 'work/builds/worker-11/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/MSleepyPanda/explain-rs 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/MSleepyPanda/explain-rs
[INFO] finished tweaking git repo https://github.com/MSleepyPanda/explain-rs
[INFO] tweaked toml for git repo https://github.com/MSleepyPanda/explain-rs written to work/builds/worker-11/source/Cargo.toml
[INFO] crate git repo https://github.com/MSleepyPanda/explain-rs 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] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"docker" "create" "-v" "/big/crater/work/builds/worker-11/target:/opt/rustwide/target:rw,Z" "-v" "/big/crater/work/builds/worker-11/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] 6c83067a45419db803bdcf0a684f1c8b0ad6fabc6844a456b58fad8c8a7e5b53
[INFO] running `"docker" "start" "-a" "6c83067a45419db803bdcf0a684f1c8b0ad6fabc6844a456b58fad8c8a7e5b53"`
[INFO] [stderr]    Compiling percent-encoding v1.0.1 (https://github.com/servo/rust-url#027450de)
[INFO] [stderr]    Compiling peresil v0.3.0 (https://github.com/shepmaster/peresil#6e4f794b)
[INFO] [stderr]    Compiling sha1 v0.3.0
[INFO] [stderr]    Compiling serde_json v1.0.8
[INFO] [stderr]    Compiling itertools v0.7.5
[INFO] [stderr]    Compiling idna v0.1.4 (https://github.com/servo/rust-url#027450de)
[INFO] [stderr]    Compiling serde_derive_internals v0.18.0
[INFO] [stderr]    Compiling fuzzy-pickles-derive v0.1.0 (https://github.com/shepmaster/fuzzy-pickles#abf5ae5b)
[INFO] [stderr] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stderr]  --> /opt/rustwide/cargo-home/git/checkouts/peresil-7403d1c1394b7448/6e4f794/src/lib.rs:1:38
[INFO] [stderr]   |
[INFO] [stderr] 1 | #![cfg_attr(feature = "combinators", feature(conservative_impl_trait))]
[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 `peresil`.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: build failed
[INFO] running `"docker" "inspect" "6c83067a45419db803bdcf0a684f1c8b0ad6fabc6844a456b58fad8c8a7e5b53"`
[INFO] running `"docker" "rm" "-f" "6c83067a45419db803bdcf0a684f1c8b0ad6fabc6844a456b58fad8c8a7e5b53"`
[INFO] [stdout] 6c83067a45419db803bdcf0a684f1c8b0ad6fabc6844a456b58fad8c8a7e5b53