[INFO] cloning repository https://github.com/akkuankka/matheriser
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/akkuankka/matheriser" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fakkuankka%2Fmatheriser", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fakkuankka%2Fmatheriser'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] c239d8c102cd360a49db0cb05b062f6951632b78
[INFO] documenting akkuankka/matheriser against 1.61.0 for beta-1.62-rustdoc-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fakkuankka%2Fmatheriser" "/workspace/builds/worker-19/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-19/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/akkuankka/matheriser 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 git repo https://github.com/akkuankka/matheriser
[INFO] finished tweaking git repo https://github.com/akkuankka/matheriser
[INFO] tweaked toml for git repo https://github.com/akkuankka/matheriser written to /workspace/builds/worker-19/source/Cargo.toml
[INFO] crate git repo https://github.com/akkuankka/matheriser already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.61.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr] `license` should be used if the package license can be expressed with a standard SPDX expression.
[INFO] [stderr] `license-file` should be used if the package uses a non-standard license.
[INFO] [stderr] See https://doc.rust-lang.org/cargo/reference/manifest.html#the-license-and-license-file-fields for more information.
[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 syn v1.0.64
[INFO] [stderr]   Downloaded directories v3.0.2
[INFO] [stderr]   Downloaded libc v0.2.95
[INFO] [stderr]   Downloaded dialoguer v0.8.0
[INFO] [stderr]   Downloaded terminal_size v0.1.17
[INFO] [stderr]   Downloaded ron v0.6.4
[INFO] [stderr]   Downloaded logos v0.12.0
[INFO] [stderr]   Downloaded console v0.14.1
[INFO] [stderr]   Downloaded beef v0.5.0
[INFO] [stderr]   Downloaded logos-derive v0.12.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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] f7d03b422a29434c21696b2f0ec6484e11e060df4aef03094122349eabfa4fc9
[INFO] running `Command { std: "docker" "start" "-a" "f7d03b422a29434c21696b2f0ec6484e11e060df4aef03094122349eabfa4fc9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "f7d03b422a29434c21696b2f0ec6484e11e060df4aef03094122349eabfa4fc9", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f7d03b422a29434c21696b2f0ec6484e11e060df4aef03094122349eabfa4fc9", kill_on_drop: false }`
[INFO] [stdout] f7d03b422a29434c21696b2f0ec6484e11e060df4aef03094122349eabfa4fc9
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-19/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] b7992111a9d63fcc761c339e44ed80e850fb40dbfd35da6df1574a360c7edd16
[INFO] running `Command { std: "docker" "start" "-a" "b7992111a9d63fcc761c339e44ed80e850fb40dbfd35da6df1574a360c7edd16", kill_on_drop: false }`
[INFO] [stderr] warning: only one of `license` or `license-file` is necessary
[INFO] [stderr] `license` should be used if the package license can be expressed with a standard SPDX expression.
[INFO] [stderr] `license-file` should be used if the package uses a non-standard license.
[INFO] [stderr] See https://doc.rust-lang.org/cargo/reference/manifest.html#the-license-and-license-file-fields for more information.
[INFO] [stderr]    Compiling libc v0.2.95
[INFO] [stderr]    Compiling proc-macro2 v1.0.24
[INFO] [stderr]    Compiling unicode-xid v0.2.1
[INFO] [stderr]    Compiling syn v1.0.64
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]     Checking unicode-width v0.1.8
[INFO] [stderr]    Compiling serde_derive v1.0.126
[INFO] [stderr]    Compiling unicode-segmentation v1.7.1
[INFO] [stderr]    Compiling serde v1.0.126
[INFO] [stderr]    Compiling fnv v1.0.7
[INFO] [stderr]     Checking ansi_term v0.11.0
[INFO] [stderr]    Compiling utf8-ranges v1.0.4
[INFO] [stderr]     Checking remove_dir_all v0.5.3
[INFO] [stderr]    Compiling beef v0.5.0
[INFO] [stderr]     Checking zeroize v1.3.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling num-integer v0.1.44
[INFO] [stderr]    Compiling num-bigint v0.4.0
[INFO] [stderr]    Compiling num-rational v0.4.0
[INFO] [stderr]    Compiling num-iter v0.1.42
[INFO] [stderr]    Compiling proc-macro-error-attr v1.0.4
[INFO] [stderr]    Compiling proc-macro-error v1.0.4
[INFO] [stderr]     Checking regex v1.5.4
[INFO] [stderr]     Checking textwrap v0.11.0
[INFO] [stderr]    Compiling heck v0.3.3
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]     Checking getrandom v0.2.3
[INFO] [stderr]     Checking atty v0.2.14
[INFO] [stderr]     Checking terminal_size v0.1.17
[INFO] [stderr]     Checking dirs-sys v0.3.6
[INFO] [stderr]     Checking clap v2.33.3
[INFO] [stderr]     Checking colored v2.0.0
[INFO] [stderr]     Checking console v0.14.1
[INFO] [stderr]     Checking directories v3.0.2
[INFO] [stderr]     Checking rand_core v0.6.2
[INFO] [stderr]     Checking num-complex v0.4.0
[INFO] [stderr]     Checking rand_chacha v0.3.0
[INFO] [stderr]     Checking rand v0.8.3
[INFO] [stderr]     Checking tempfile v3.2.0
[INFO] [stderr]     Checking dialoguer v0.8.0
[INFO] [stderr]     Checking num v0.4.0
[INFO] [stderr]    Compiling logos-derive v0.12.0
[INFO] [stderr]    Compiling structopt-derive v0.4.14
[INFO] [stderr]     Checking structopt v0.3.21
[INFO] [stderr]     Checking logos v0.12.0
[INFO] [stderr]     Checking ron v0.6.4
[INFO] [stderr]  Documenting matheriser v0.2.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:1
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(negative_impls)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:2:1
[INFO] [stdout]   |
[INFO] [stdout] 2 | #![feature(drain_filter)]
[INFO] [stdout]   | ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: Compilation failed, aborting rustdoc
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 3 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 `matheriser`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name matheriser src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=7a87ae26c347090a -L dependency=/opt/rustwide/target/debug/deps --extern colored=/opt/rustwide/target/debug/deps/libcolored-b7a6bbcccc8fad05.rmeta --extern dialoguer=/opt/rustwide/target/debug/deps/libdialoguer-5992c65d96237853.rmeta --extern directories=/opt/rustwide/target/debug/deps/libdirectories-cfb329a914942aa1.rmeta --extern logos=/opt/rustwide/target/debug/deps/liblogos-5b63defbf1af6e09.rmeta --extern num=/opt/rustwide/target/debug/deps/libnum-bc3d236763400285.rmeta --extern ron=/opt/rustwide/target/debug/deps/libron-1703f8d312980d1a.rmeta --extern serde=/opt/rustwide/target/debug/deps/libserde-bcca7355634f41ac.rmeta --extern structopt=/opt/rustwide/target/debug/deps/libstructopt-d2ac751d0988f71a.rmeta --cap-lints=warn --crate-version 0.2.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "b7992111a9d63fcc761c339e44ed80e850fb40dbfd35da6df1574a360c7edd16", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b7992111a9d63fcc761c339e44ed80e850fb40dbfd35da6df1574a360c7edd16", kill_on_drop: false }`
[INFO] [stdout] b7992111a9d63fcc761c339e44ed80e850fb40dbfd35da6df1574a360c7edd16