[INFO] cloning repository https://github.com/rroohhh/mtf-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/rroohhh/mtf-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frroohhh%2Fmtf-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Frroohhh%2Fmtf-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 6680ff51aa4cda57da2ec6b33d58f004b181124e
[INFO] documenting rroohhh/mtf-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%2Frroohhh%2Fmtf-rs" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/rroohhh/mtf-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/rroohhh/mtf-rs
[INFO] finished tweaking git repo https://github.com/rroohhh/mtf-rs
[INFO] tweaked toml for git repo https://github.com/rroohhh/mtf-rs written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/rroohhh/mtf-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-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] 84bc96bb9c326f20aae1435e916e6e910c4bdd1dc644976b827b2474633e6264
[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" "84bc96bb9c326f20aae1435e916e6e910c4bdd1dc644976b827b2474633e6264", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "84bc96bb9c326f20aae1435e916e6e910c4bdd1dc644976b827b2474633e6264", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84bc96bb9c326f20aae1435e916e6e910c4bdd1dc644976b827b2474633e6264", kill_on_drop: false }`
[INFO] [stdout] 84bc96bb9c326f20aae1435e916e6e910c4bdd1dc644976b827b2474633e6264
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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] a79ee0f888a59f89c0a7dcf23e828b297a4d9abbc634cf483c19349c31b41caf
[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" "a79ee0f888a59f89c0a7dcf23e828b297a4d9abbc634cf483c19349c31b41caf", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling syn v0.15.43
[INFO] [stderr]    Compiling cc v1.0.38
[INFO] [stderr]    Compiling jetscii v0.4.4
[INFO] [stderr]     Checking memmap v0.7.0
[INFO] [stderr]    Compiling backtrace-sys v0.1.31
[INFO] [stderr]     Checking backtrace v0.3.34
[INFO] [stderr]    Compiling synstructure v0.10.2
[INFO] [stderr]    Compiling failure_derive v0.1.5
[INFO] [stderr]     Checking failure v0.1.5
[INFO] [stderr]  Documenting mtf v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error: expected one of `!`, `.`, `::`, `;`, `?`, `{`, `}`, or an operator, found keyword `let`
[INFO] [stdout]    --> src/main.rs:919:9
[INFO] [stdout]     |
[INFO] [stdout] 918 | i
[INFO] [stdout]     |  - expected one of 8 possible tokens
[INFO] [stdout] 919 |         let header = StreamHeader {
[INFO] [stdout]     |         ^^^ unexpected token
[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] [stderr] error: Could not document `mtf`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name mtf src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi --document-private-items -L dependency=/opt/rustwide/target/debug/deps --extern bitflags=/opt/rustwide/target/debug/deps/libbitflags-bef5630b82c3f945.rmeta --extern byteorder=/opt/rustwide/target/debug/deps/libbyteorder-6d64c9de8ec8b357.rmeta --extern failure=/opt/rustwide/target/debug/deps/libfailure-182d13b12f8bbd93.rmeta --extern jetscii=/opt/rustwide/target/debug/deps/libjetscii-3abc80bf7feac1ee.rmeta --extern memmap=/opt/rustwide/target/debug/deps/libmemmap-4968721429311796.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "a79ee0f888a59f89c0a7dcf23e828b297a4d9abbc634cf483c19349c31b41caf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "a79ee0f888a59f89c0a7dcf23e828b297a4d9abbc634cf483c19349c31b41caf", kill_on_drop: false }`
[INFO] [stdout] a79ee0f888a59f89c0a7dcf23e828b297a4d9abbc634cf483c19349c31b41caf