[INFO] cloning repository https://github.com/LemonHX/optimistic_lock_coupling_rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/LemonHX/optimistic_lock_coupling_rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLemonHX%2Foptimistic_lock_coupling_rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLemonHX%2Foptimistic_lock_coupling_rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 1265a873371e39cd99818573cd94117ea3db66da
[INFO] documenting LemonHX/optimistic_lock_coupling_rs against 1.75.0 for beta-1.76-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FLemonHX%2Foptimistic_lock_coupling_rs" "/workspace/builds/worker-2-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-2-tc1/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/LemonHX/optimistic_lock_coupling_rs 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 git repo https://github.com/LemonHX/optimistic_lock_coupling_rs
[INFO] finished tweaking git repo https://github.com/LemonHX/optimistic_lock_coupling_rs
[INFO] tweaked toml for git repo https://github.com/LemonHX/optimistic_lock_coupling_rs written to /workspace/builds/worker-2-tc1/source/Cargo.toml
[INFO] crate git repo https://github.com/LemonHX/optimistic_lock_coupling_rs already has a lockfile, it will not be regenerated
[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 cast v0.2.4
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] ecfa61e1366c45ab62c54c4bd6f27bcc79e53792cb20ae30a921d54fa0a87b9f
[INFO] running `Command { std: "docker" "start" "-a" "ecfa61e1366c45ab62c54c4bd6f27bcc79e53792cb20ae30a921d54fa0a87b9f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ecfa61e1366c45ab62c54c4bd6f27bcc79e53792cb20ae30a921d54fa0a87b9f", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ecfa61e1366c45ab62c54c4bd6f27bcc79e53792cb20ae30a921d54fa0a87b9f", kill_on_drop: false }`
[INFO] [stdout] ecfa61e1366c45ab62c54c4bd6f27bcc79e53792cb20ae30a921d54fa0a87b9f
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-2-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] 6390cf69790aa4859838433142ec4588b2079401efd55403839c497d19cfaa76
[INFO] running `Command { std: "docker" "start" "-a" "6390cf69790aa4859838433142ec4588b2079401efd55403839c497d19cfaa76", kill_on_drop: false }`
[INFO] [stderr]  Documenting optimistic_lock_coupling v0.2.5 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(negative_impls)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(unboxed_closures)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:3:1
[INFO] [stdout]   |
[INFO] [stdout] 3 | #![feature(stmt_expr_attributes)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `optimistic_lock_coupling`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `/opt/rustwide/rustup-home/toolchains/1.75.0-x86_64-unknown-linux-gnu/bin/rustdoc --edition=2018 --crate-type lib --crate-name optimistic_lock_coupling src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=bd77e6c45bfe3aff -L dependency=/opt/rustwide/target/debug/deps --cap-lints=warn --crate-version 0.2.5` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "6390cf69790aa4859838433142ec4588b2079401efd55403839c497d19cfaa76", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6390cf69790aa4859838433142ec4588b2079401efd55403839c497d19cfaa76", kill_on_drop: false }`
[INFO] [stdout] 6390cf69790aa4859838433142ec4588b2079401efd55403839c497d19cfaa76
