[INFO] fetching crate mmime 0.1.2...
[INFO] documenting mmime-0.1.2 against 1.46.0 for beta-1.47-rustdoc-1
[INFO] extracting crate mmime 0.1.2 into /workspace/builds/worker-0/source
[INFO] validating manifest of crates.io crate mmime 0.1.2 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 crates.io crate mmime 0.1.2
[INFO] finished tweaking crates.io crate mmime 0.1.2
[INFO] tweaked toml for crates.io crate mmime 0.1.2 written to /workspace/builds/worker-0/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.46.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[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] [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] ecc7602883a1a9453aab2e269124628195f2b3f89808f111c596e2f4fd932a41
[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" "ecc7602883a1a9453aab2e269124628195f2b3f89808f111c596e2f4fd932a41", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "ecc7602883a1a9453aab2e269124628195f2b3f89808f111c596e2f4fd932a41", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ecc7602883a1a9453aab2e269124628195f2b3f89808f111c596e2f4fd932a41", kill_on_drop: false }`
[INFO] [stdout] ecc7602883a1a9453aab2e269124628195f2b3f89808f111c596e2f4fd932a41
[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] 4937c6f8a1aa6fa62fc957fe00f2f3ad9b1c472a1c8c294d6e62cc28bde58f44
[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" "4937c6f8a1aa6fa62fc957fe00f2f3ad9b1c472a1c8c294d6e62cc28bde58f44", kill_on_drop: false }`
[INFO] [stderr]     Checking charset v0.1.2
[INFO] [stderr]  Documenting mmime v0.1.2 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> src/lib.rs:10:1
[INFO] [stdout]    |
[INFO] [stdout] 10 | #![feature(extern_types)]
[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:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | #![feature(const_raw_ptr_to_usize_cast)]
[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:12:1
[INFO] [stdout]    |
[INFO] [stdout] 12 | #![feature(ptr_wrapping_offset_from)]
[INFO] [stdout]    | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 4 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 `mmime`.
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type lib --crate-name mmime 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 charset=/opt/rustwide/target/debug/deps/libcharset-c5c5a4eeb6d7cfd8.rmeta --extern chrono=/opt/rustwide/target/debug/deps/libchrono-8ddd5e37f7f73bd8.rmeta --extern hex=/opt/rustwide/target/debug/deps/libhex-c4c99eb62be651d1.rmeta --extern lazy_static=/opt/rustwide/target/debug/deps/liblazy_static-57a7edc7f441d44c.rmeta --extern libc=/opt/rustwide/target/debug/deps/liblibc-1ad3ad1e20beb97f.rmeta --extern memmap=/opt/rustwide/target/debug/deps/libmemmap-5e36c0d4fd2fa327.rmeta --extern rand=/opt/rustwide/target/debug/deps/librand-9b356e0eb33fe2d1.rmeta --cap-lints=warn` (exit code: 1)
[INFO] running `Command { std: "docker" "inspect" "4937c6f8a1aa6fa62fc957fe00f2f3ad9b1c472a1c8c294d6e62cc28bde58f44", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4937c6f8a1aa6fa62fc957fe00f2f3ad9b1c472a1c8c294d6e62cc28bde58f44", kill_on_drop: false }`
[INFO] [stdout] 4937c6f8a1aa6fa62fc957fe00f2f3ad9b1c472a1c8c294d6e62cc28bde58f44