[INFO] cloning repository https://github.com/tomafro/flashlight
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/tomafro/flashlight" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftomafro%2Fflashlight", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftomafro%2Fflashlight'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] e7529d89eb9d97841151555e04a68763e7d1b0c0
[INFO] documenting tomafro/flashlight 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%2Ftomafro%2Fflashlight" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/tomafro/flashlight 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/tomafro/flashlight
[INFO] finished tweaking git repo https://github.com/tomafro/flashlight
[INFO] tweaked toml for git repo https://github.com/tomafro/flashlight written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/tomafro/flashlight 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] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 5e2735d470e30254b2519465ac72c9036dfc6ef3dcf0f598f410744d5189f679
[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" "5e2735d470e30254b2519465ac72c9036dfc6ef3dcf0f598f410744d5189f679", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "5e2735d470e30254b2519465ac72c9036dfc6ef3dcf0f598f410744d5189f679", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "5e2735d470e30254b2519465ac72c9036dfc6ef3dcf0f598f410744d5189f679", kill_on_drop: false }`
[INFO] [stdout] 5e2735d470e30254b2519465ac72c9036dfc6ef3dcf0f598f410744d5189f679
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] fb995d33202cee25eddeebad6b5cccc914997404d3f0f06beba6bed400482837
[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" "fb995d33202cee25eddeebad6b5cccc914997404d3f0f06beba6bed400482837", kill_on_drop: false }`
[INFO] [stderr]     Checking libc v0.2.39
[INFO] [stderr]    Compiling proc-macro-hack-impl v0.4.0
[INFO] [stderr]    Compiling regex v0.2.10
[INFO] [stderr]     Checking serde v1.0.34
[INFO] [stderr]    Compiling unindent v0.1.2
[INFO] [stderr]     Checking num-traits v0.2.2
[INFO] [stderr]     Checking itoa v0.4.1
[INFO] [stderr]    Compiling proc-macro2 v0.2.3
[INFO] [stderr]     Checking regex-syntax v0.5.3
[INFO] [stderr]     Checking thread_local v0.3.5
[INFO] [stderr]    Compiling proc-macro-hack v0.4.0
[INFO] [stderr]    Compiling quote v0.4.2
[INFO] [stderr]    Compiling indoc-impl v0.2.3
[INFO] [stderr]     Checking memchr v2.0.1
[INFO] [stderr]     Checking isatty v0.1.6
[INFO] [stderr]    Compiling syn v0.12.14
[INFO] [stderr]     Checking aho-corasick v0.6.4
[INFO] [stderr]     Checking indoc v0.2.3
[INFO] [stderr]    Compiling serde_derive_internals v0.22.0
[INFO] [stderr]    Compiling serde_derive v1.0.34
[INFO] [stderr]     Checking serde_json v1.0.13
[INFO] [stderr]     Checking docopt v0.8.3
[INFO] [stderr]  Documenting flashlight 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:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(test)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[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: Could not document `flashlight`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --crate-type lib --crate-name flashlight src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern docopt=/opt/rustwide/target/debug/deps/libdocopt-1f6c6c231fbe3a51.rmeta --extern indoc=/opt/rustwide/target/debug/deps/libindoc-9f70546c0eb11f9f.rmeta --extern isatty=/opt/rustwide/target/debug/deps/libisatty-35e5deff56bf5513.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-cf6de5a7670865a1.rmeta --extern regex=/opt/rustwide/target/debug/deps/libregex-1667cc9baeb58d6c.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-68cb45ce4ba3ffde.rmeta --extern serde_derive=/opt/rustwide/target/debug/deps/libserde_derive-bc79a2b2607d4afa.so --extern serde_json=/opt/rustwide/target/debug/deps/libserde_json-3a94cfe306c4cdb2.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "fb995d33202cee25eddeebad6b5cccc914997404d3f0f06beba6bed400482837", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "fb995d33202cee25eddeebad6b5cccc914997404d3f0f06beba6bed400482837", kill_on_drop: false }`
[INFO] [stdout] fb995d33202cee25eddeebad6b5cccc914997404d3f0f06beba6bed400482837