[INFO] cloning repository https://github.com/light4/riscv-baremetal-rust-helloworld
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/light4/riscv-baremetal-rust-helloworld" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flight4%2Friscv-baremetal-rust-helloworld", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Flight4%2Friscv-baremetal-rust-helloworld'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3d72b5c58d3e2fa86b11370a78886fdf8deee0bf
[INFO] documenting light4/riscv-baremetal-rust-helloworld 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%2Flight4%2Friscv-baremetal-rust-helloworld" "/workspace/builds/worker-4/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/light4/riscv-baremetal-rust-helloworld 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] removed /workspace/builds/worker-4/source/.cargo/config.toml
[INFO] removed /workspace/builds/worker-4/source/rust-toolchain
[INFO] started tweaking git repo https://github.com/light4/riscv-baremetal-rust-helloworld
[INFO] finished tweaking git repo https://github.com/light4/riscv-baremetal-rust-helloworld
[INFO] tweaked toml for git repo https://github.com/light4/riscv-baremetal-rust-helloworld written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/light4/riscv-baremetal-rust-helloworld 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]  Downloading crates ...
[INFO] [stderr]   Downloaded riscv-target v0.1.2
[INFO] [stderr]   Downloaded r0 v1.0.0
[INFO] [stderr]   Downloaded riscv v0.6.0
[INFO] [stderr]   Downloaded riscv-rt-macros v0.1.6
[INFO] [stderr]   Downloaded riscv-rt v0.8.0
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] 50e472b7ed1bb4e62f0f947ad2c1ffb6ee18cd3ddf0be0f792e455d897fc431e
[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" "50e472b7ed1bb4e62f0f947ad2c1ffb6ee18cd3ddf0be0f792e455d897fc431e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "50e472b7ed1bb4e62f0f947ad2c1ffb6ee18cd3ddf0be0f792e455d897fc431e", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "50e472b7ed1bb4e62f0f947ad2c1ffb6ee18cd3ddf0be0f792e455d897fc431e", kill_on_drop: false }`
[INFO] [stdout] 50e472b7ed1bb4e62f0f947ad2c1ffb6ee18cd3ddf0be0f792e455d897fc431e
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 262b8d1e221d3ab31a9269d615e611a7fc7fcf0f34a28ca5fe4df466e5b2daf5
[INFO] running `Command { std: "docker" "start" "-a" "262b8d1e221d3ab31a9269d615e611a7fc7fcf0f34a28ca5fe4df466e5b2daf5", kill_on_drop: false }`
[INFO] [stderr]    Compiling once_cell v1.5.2
[INFO] [stderr]    Compiling proc-macro2 v0.4.30
[INFO] [stderr]    Compiling unicode-xid v0.1.0
[INFO] [stderr]    Compiling rand_core v0.4.2
[INFO] [stderr]     Checking bit_field v0.10.1
[INFO] [stderr]     Checking r0 v1.0.0
[INFO] [stderr]     Checking panic-halt v0.2.0
[INFO] [stderr]    Compiling bare-metal v0.2.5
[INFO] [stderr]    Compiling thread_local v1.1.3
[INFO] [stderr]    Compiling rand_core v0.3.1
[INFO] [stderr]    Compiling rand v0.5.6
[INFO] [stderr]    Compiling regex v1.4.3
[INFO] [stderr]    Compiling quote v0.6.13
[INFO] [stderr]    Compiling syn v0.15.44
[INFO] [stderr]    Compiling riscv-target v0.1.2
[INFO] [stderr]    Compiling riscv v0.6.0
[INFO] [stderr]    Compiling riscv-rt v0.8.0
[INFO] [stderr]    Compiling riscv-rt-macros v0.1.6
[INFO] [stderr]  Documenting riscv-baremetal-rust-helloworld v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(llvm_asm)]
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error[E0635]: unknown feature `llvm_asm`
[INFO] [stdout]  --> src/main.rs:1:12
[INFO] [stdout]   |
[INFO] [stdout] 1 | #![feature(llvm_asm)]
[INFO] [stdout]   |            ^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to 2 previous errors
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] Some errors have detailed explanations: E0554, E0635.
[INFO] [stdout] 
[INFO] [stdout] For more information about an error, try `rustc --explain E0554`.
[INFO] [stdout] 
[INFO] [stderr] error: could not document `riscv-baremetal-rust-helloworld`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   process didn't exit successfully: `rustdoc --edition=2018 --crate-type bin --crate-name riscv_baremetal_rust_helloworld src/main.rs -o /opt/rustwide/target/doc --error-format=json --json=diagnostic-rendered-ansi,artifacts,future-incompat --document-private-items -C metadata=70dc28e2062d2e16 -L dependency=/opt/rustwide/target/debug/deps --extern panic_halt=/opt/rustwide/target/debug/deps/libpanic_halt-4b6ee28e78cbac24.rmeta --extern r0=/opt/rustwide/target/debug/deps/libr0-20a6111180e769fa.rmeta --extern riscv_rt=/opt/rustwide/target/debug/deps/libriscv_rt-878c94c6515f27ba.rmeta --cap-lints=warn --crate-version 0.1.0` (exit status: 1)
[INFO] running `Command { std: "docker" "inspect" "262b8d1e221d3ab31a9269d615e611a7fc7fcf0f34a28ca5fe4df466e5b2daf5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "262b8d1e221d3ab31a9269d615e611a7fc7fcf0f34a28ca5fe4df466e5b2daf5", kill_on_drop: false }`
[INFO] [stdout] 262b8d1e221d3ab31a9269d615e611a7fc7fcf0f34a28ca5fe4df466e5b2daf5