[INFO] cloning repository https://github.com/benmkw/zpng_rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/benmkw/zpng_rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbenmkw%2Fzpng_rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbenmkw%2Fzpng_rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 839a84b0f30e841f7197d36e4c526a86aef7db19
[INFO] documenting benmkw/zpng_rs against 1.46.0 for beta-1.47-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fbenmkw%2Fzpng_rs" "/workspace/builds/worker-0/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-0/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/benmkw/zpng_rs on toolchain 1.46.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/benmkw/zpng_rs
[INFO] finished tweaking git repo https://github.com/benmkw/zpng_rs
[INFO] tweaked toml for git repo https://github.com/benmkw/zpng_rs written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] crate git repo https://github.com/benmkw/zpng_rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 532d915cb764be2f0a3ad08acda568e7c016bd1b9ae5218eed71e03869888d10
[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" "532d915cb764be2f0a3ad08acda568e7c016bd1b9ae5218eed71e03869888d10", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "532d915cb764be2f0a3ad08acda568e7c016bd1b9ae5218eed71e03869888d10", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "532d915cb764be2f0a3ad08acda568e7c016bd1b9ae5218eed71e03869888d10", kill_on_drop: false }`
[INFO] [stdout] 532d915cb764be2f0a3ad08acda568e7c016bd1b9ae5218eed71e03869888d10
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0/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" "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" "rustops/crates-build-env@sha256:d92eaeed33fa75130ca1ee6c8a01d1ffb62bac859dfdfb3450e3e5d1c0146529" "/opt/rustwide/cargo-home/bin/cargo" "+1.46.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b5c6b2c7bf55f143570ec20acc8baad10092f1ae1d6e0ed243922dd2bbf404de
[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" "b5c6b2c7bf55f143570ec20acc8baad10092f1ae1d6e0ed243922dd2bbf404de", kill_on_drop: false }`
[INFO] [stderr]    Compiling syn v1.0.17
[INFO] [stderr]     Checking fallible-iterator v0.2.0
[INFO] [stderr]     Checking findshlibs v0.5.0
[INFO] [stderr]     Checking memmap v0.7.0
[INFO] [stderr]    Compiling cc v1.0.50
[INFO] [stderr]     Checking png v0.16.2
[INFO] [stderr]     Checking gimli v0.20.0
[INFO] [stderr]     Checking image v0.23.3
[INFO] [stderr]    Compiling backtrace-sys v0.1.35
[INFO] [stderr]    Compiling zstd-sys v1.4.15+zstd.1.4.4
[INFO] [stderr]     Checking addr2line v0.11.0
[INFO] [stderr]    Compiling scroll_derive v0.10.1
[INFO] [stderr]    Compiling argh_derive v0.1.1
[INFO] [stderr]     Checking scroll v0.10.1
[INFO] [stderr]     Checking goblin v0.2.1
[INFO] [stderr]     Checking argh v0.1.3
[INFO] [stderr]     Checking backtrace v0.3.46
[INFO] [stderr]     Checking color-backtrace v0.3.0
[INFO] [stderr]     Checking zstd-safe v2.0.3+zstd.1.4.4
[INFO] [stderr]     Checking zstd v0.5.1+zstd.1.4.4
[INFO] [stderr]     Checking zpng_rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr]  Documenting zpng_rs v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/lib.rs:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(const_generics)]
[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:7:1
[INFO] [stdout]   |
[INFO] [stdout] 7 | #![feature(const_generics)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[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 E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `zpng_rs`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] For more information about this error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: build failed
[INFO] running `Command { std: "docker" "inspect" "b5c6b2c7bf55f143570ec20acc8baad10092f1ae1d6e0ed243922dd2bbf404de", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b5c6b2c7bf55f143570ec20acc8baad10092f1ae1d6e0ed243922dd2bbf404de", kill_on_drop: false }`
[INFO] [stdout] b5c6b2c7bf55f143570ec20acc8baad10092f1ae1d6e0ed243922dd2bbf404de