[INFO] fetching crate mula 0.1.1...
[INFO] documenting mula-0.1.1 against beta-2021-08-01 for beta-1.55-rustdoc-1
[INFO] extracting crate mula 0.1.1 into /workspace/builds/worker-46/source
[INFO] validating manifest of crates.io crate mula 0.1.1 on toolchain beta-2021-08-01
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mula 0.1.1
[INFO] finished tweaking crates.io crate mula 0.1.1
[INFO] tweaked toml for crates.io crate mula 0.1.1 written to /workspace/builds/worker-46/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2021-08-01" "fetch" "--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] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded spmc v0.3.0
[INFO] [stderr]   Downloaded mula_proc_macro v0.1.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 851c9c6bde6d28111bf4be541325342a0a6b837c2c146847a6e87f211f7927b0
[INFO] running `Command { std: "docker" "start" "-a" "851c9c6bde6d28111bf4be541325342a0a6b837c2c146847a6e87f211f7927b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "851c9c6bde6d28111bf4be541325342a0a6b837c2c146847a6e87f211f7927b0", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "851c9c6bde6d28111bf4be541325342a0a6b837c2c146847a6e87f211f7927b0", kill_on_drop: false }`
[INFO] [stdout] 851c9c6bde6d28111bf4be541325342a0a6b837c2c146847a6e87f211f7927b0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-46/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2021-08-01" "doc" "--frozen" "--no-deps" "--document-private-items" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 43e4482339a156249fe0f816459b327e61665dd4276b643fe0e46ebce0991b99
[INFO] running `Command { std: "docker" "start" "-a" "43e4482339a156249fe0f816459b327e61665dd4276b643fe0e46ebce0991b99", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling proc-macro2 v1.0.28
[INFO] [stderr]    Compiling syn v1.0.74
[INFO] [stderr]     Checking spmc v0.3.0
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling mula_proc_macro v0.1.0
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the beta release channel
[INFO] [stdout]  --> /opt/rustwide/cargo-home/registry/src/github.com-1ecc6299db9ec823/mula_proc_macro-0.1.0/src/lib.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(proc_macro_diagnostic)]
[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 `mula_proc_macro` due to 2 previous errors
[INFO] running `Command { std: "docker" "inspect" "43e4482339a156249fe0f816459b327e61665dd4276b643fe0e46ebce0991b99", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "43e4482339a156249fe0f816459b327e61665dd4276b643fe0e46ebce0991b99", kill_on_drop: false }`
[INFO] [stdout] 43e4482339a156249fe0f816459b327e61665dd4276b643fe0e46ebce0991b99
