[INFO] fetching crate mantle-macros 0.2.1...
[INFO] documenting mantle-macros-0.2.1 against 1.61.0 for beta-1.62-rustdoc-1
[INFO] extracting crate mantle-macros 0.2.1 into /workspace/builds/worker-17/source
[INFO] validating manifest of crates.io crate mantle-macros 0.2.1 on toolchain 1.61.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mantle-macros 0.2.1
[INFO] finished tweaking crates.io crate mantle-macros 0.2.1
[INFO] tweaked toml for crates.io crate mantle-macros 0.2.1 written to /workspace/builds/worker-17/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] edcf0cc0898492332d4ace6e77906d8066663fcfc3241bcdf58acfb89cde5bfe
[INFO] running `Command { std: "docker" "start" "-a" "edcf0cc0898492332d4ace6e77906d8066663fcfc3241bcdf58acfb89cde5bfe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "edcf0cc0898492332d4ace6e77906d8066663fcfc3241bcdf58acfb89cde5bfe", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "edcf0cc0898492332d4ace6e77906d8066663fcfc3241bcdf58acfb89cde5bfe", kill_on_drop: false }`
[INFO] [stdout] edcf0cc0898492332d4ace6e77906d8066663fcfc3241bcdf58acfb89cde5bfe
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-17/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" "ghcr.io/rust-lang/crates-build-env/linux@sha256:d190cb871061d98bc6d0581d85cb2ecb09a0f8a142ba5463de30be9999fc3251" "/opt/rustwide/cargo-home/bin/cargo" "+1.61.0" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] ef6cb914367b22f55a4deb148719ec8a39f065f81940012f715115ec0d05e8db
[INFO] running `Command { std: "docker" "start" "-a" "ef6cb914367b22f55a4deb148719ec8a39f065f81940012f715115ec0d05e8db", kill_on_drop: false }`
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling proc-macro-hack v0.5.19
[INFO] [stderr]     Checking unicode-xid v0.1.0
[INFO] [stderr]    Compiling crunchy v0.2.2
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]     Checking tiny-keccak v1.5.0
[INFO] [stderr]     Checking quote v0.6.13
[INFO] [stderr]    Compiling proc-quote-impl v0.2.2
[INFO] [stderr]     Checking proc-quote v0.2.2
[INFO] [stderr]  Documenting mantle-macros v0.2.1 (/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(proc_macro_diagnostic, type_ascription)]
[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 `mantle-macros`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type proc-macro --crate-name mantle_macros src/lib.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=4c098e54257663a2 -L dependency=/opt/rustwide/target/debug/deps --extern proc_macro2=/opt/rustwide/target/debug/deps/libproc_macro2-42b8f402e5615b33.rmeta --extern proc_quote=/opt/rustwide/target/debug/deps/libproc_quote-773755e05d77583c.rmeta --extern syn=/opt/rustwide/target/debug/deps/libsyn-9e94d3a07e49f968.rmeta --extern tiny_keccak=/opt/rustwide/target/debug/deps/libtiny_keccak-c0867e2891fca60f.rmeta --extern proc_macro --cap-lints=warn --crate-version 0.2.1` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "ef6cb914367b22f55a4deb148719ec8a39f065f81940012f715115ec0d05e8db", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "ef6cb914367b22f55a4deb148719ec8a39f065f81940012f715115ec0d05e8db", kill_on_drop: false }`
[INFO] [stdout] ef6cb914367b22f55a4deb148719ec8a39f065f81940012f715115ec0d05e8db