[INFO] fetching crate zcfg_flag_parser 0.2.0...
[INFO] documenting zcfg_flag_parser-0.2.0 against 1.75.0 for beta-1.76-rustdoc-1
[INFO] extracting crate zcfg_flag_parser 0.2.0 into /workspace/builds/worker-4-tc1/source
[INFO] validating manifest of crates.io crate zcfg_flag_parser 0.2.0 on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate zcfg_flag_parser 0.2.0
[INFO] finished tweaking crates.io crate zcfg_flag_parser 0.2.0
[INFO] tweaked toml for crates.io crate zcfg_flag_parser 0.2.0 written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded zcfg v0.2.0
[INFO] [stderr]   Downloaded itertools v0.6.5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 1f3aeeb7f6773fe816735a7a36e13fd038c18f442ee944cdcf26167755154822
[INFO] running `Command { std: "docker" "start" "-a" "1f3aeeb7f6773fe816735a7a36e13fd038c18f442ee944cdcf26167755154822", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1f3aeeb7f6773fe816735a7a36e13fd038c18f442ee944cdcf26167755154822", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1f3aeeb7f6773fe816735a7a36e13fd038c18f442ee944cdcf26167755154822", kill_on_drop: false }`
[INFO] [stdout] 1f3aeeb7f6773fe816735a7a36e13fd038c18f442ee944cdcf26167755154822
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4-tc1/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "RUSTDOCFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 34a535eb451a318d49bdafd312d7a49ee90d8ba660e11c6240c8011aa0d579ab
[INFO] running `Command { std: "docker" "start" "-a" "34a535eb451a318d49bdafd312d7a49ee90d8ba660e11c6240c8011aa0d579ab", kill_on_drop: false }`
[INFO] [stderr]     Checking lazy_static v0.2.11
[INFO] [stderr]     Checking either v1.9.0
[INFO] [stderr]     Checking zcfg v0.2.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/index.crates.io-6f17d22bba15001f/zcfg-0.2.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(used)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^ help: remove the attribute
[INFO] [stdout]   |
[INFO] [stdout]   = help: the feature `used` has been stable since `1.30.0` and no longer requires an attribute to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Checking itertools v0.6.5
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `zcfg` (lib) due to 2 previous errors
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] running `Command { std: "docker" "inspect" "34a535eb451a318d49bdafd312d7a49ee90d8ba660e11c6240c8011aa0d579ab", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "34a535eb451a318d49bdafd312d7a49ee90d8ba660e11c6240c8011aa0d579ab", kill_on_drop: false }`
[INFO] [stdout] 34a535eb451a318d49bdafd312d7a49ee90d8ba660e11c6240c8011aa0d579ab
