[INFO] updating cached repository https://github.com/csschan/merkle
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] bef4d0d93baf840fec58c8e9f503a1548ac8bdc9
[INFO] documenting csschan/merkle against master#394e1b40d264aa6928811919c1124fa248e7d802 for pr-73566
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fcsschan%2Fmerkle" "/workspace/builds/worker-14/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-14/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/csschan/merkle on toolchain 394e1b40d264aa6928811919c1124fa248e7d802
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/csschan/merkle
[INFO] finished tweaking git repo https://github.com/csschan/merkle
[INFO] tweaked toml for git repo https://github.com/csschan/merkle written to /workspace/builds/worker-14/source/Cargo.toml
[INFO] crate git repo https://github.com/csschan/merkle already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 76b0a06e76339c174e698a613f91fa6ca59edf8d50c2df13b778a25a6e552e01
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "76b0a06e76339c174e698a613f91fa6ca59edf8d50c2df13b778a25a6e552e01", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "76b0a06e76339c174e698a613f91fa6ca59edf8d50c2df13b778a25a6e552e01", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "76b0a06e76339c174e698a613f91fa6ca59edf8d50c2df13b778a25a6e552e01", kill_on_drop: false }`
[INFO] [stdout] 76b0a06e76339c174e698a613f91fa6ca59edf8d50c2df13b778a25a6e552e01
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-14/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTDOCFLAGS=--cap-lints=forbid" "-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@sha256:819119df93c0f5eca3f29186f14981ef29945a311854d7222af07488600a2584" "/opt/rustwide/cargo-home/bin/cargo" "+394e1b40d264aa6928811919c1124fa248e7d802" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] e3a06903dd3c081a64a7b35bc908d997957c61220b43b78c3666bdb1cd8cc486
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "e3a06903dd3c081a64a7b35bc908d997957c61220b43b78c3666bdb1cd8cc486", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.67
[INFO] [stderr]    Compiling gcc v0.3.55
[INFO] [stderr]     Checking rustc-serialize v0.3.24
[INFO] [stderr]    Compiling rust-crypto v0.2.36
[INFO] [stderr]     Checking rand v0.4.6
[INFO] [stderr]     Checking time v0.1.42
[INFO] [stderr]     Checking rand v0.3.23
[INFO] [stderr]  Documenting merkle v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0658]: use of unstable library feature 'test'
[INFO] [stdout]   --> src/lib.rs:14:1
[INFO] [stdout]    |
[INFO] [stdout] 14 | extern crate test;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: see issue #50297 <https://github.com/rust-lang/rust/issues/50297> for more information
[INFO] [stdout]    = help: add `#![feature(test)]` to the crate attributes to enable
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0658`.
[INFO] [stdout] 
[INFO] [stderr] error: Could not document `merkle`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name merkle src/lib.rs -o /opt/rustwide/target/doc --cfg 'feature="default"' --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern crypto=/opt/rustwide/target/debug/deps/libcrypto-aacaa42e15d55814.rmeta --extern rustc_serialize=/opt/rustwide/target/debug/deps/librustc_serialize-7ddf6b4d13e0395e.rmeta --cap-lints=forbid` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "e3a06903dd3c081a64a7b35bc908d997957c61220b43b78c3666bdb1cd8cc486", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "e3a06903dd3c081a64a7b35bc908d997957c61220b43b78c3666bdb1cd8cc486", kill_on_drop: false }`
[INFO] [stdout] e3a06903dd3c081a64a7b35bc908d997957c61220b43b78c3666bdb1cd8cc486