[INFO] cloning repository https://github.com/ptmalloc/rcoreLearn
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ptmalloc/rcoreLearn" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fptmalloc%2FrcoreLearn", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fptmalloc%2FrcoreLearn'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 3b648c7d8ebfe4dc0f1a221c0f7375088c6f91cf
[INFO] testing ptmalloc/rcoreLearn against 1.49.0 for beta-1.50-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fptmalloc%2FrcoreLearn" "/workspace/builds/worker-6/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-6/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/ptmalloc/rcoreLearn on toolchain 1.49.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] removed /workspace/builds/worker-6/source/.cargo/config
[INFO] started tweaking git repo https://github.com/ptmalloc/rcoreLearn
[INFO] finished tweaking git repo https://github.com/ptmalloc/rcoreLearn
[INFO] tweaked toml for git repo https://github.com/ptmalloc/rcoreLearn written to /workspace/builds/worker-6/source/Cargo.toml
[INFO] crate git repo https://github.com/ptmalloc/rcoreLearn already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.49.0" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3f3909c40cf325de150b4a2b03a99896b6646a3a027e0e7a7a96af3c829dafcf
[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" "3f3909c40cf325de150b4a2b03a99896b6646a3a027e0e7a7a96af3c829dafcf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3f3909c40cf325de150b4a2b03a99896b6646a3a027e0e7a7a96af3c829dafcf", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3f3909c40cf325de150b4a2b03a99896b6646a3a027e0e7a7a96af3c829dafcf", kill_on_drop: false }`
[INFO] [stdout] 3f3909c40cf325de150b4a2b03a99896b6646a3a027e0e7a7a96af3c829dafcf
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-6/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" "RUSTFLAGS=--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:b8eeb62f26c39b23691079a6cb6de528d8e88b4d71a8f6b1d30f8ba7d9c16de9" "/opt/rustwide/cargo-home/bin/cargo" "+1.49.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c1630a38d30bd8d6bcd4267fcd24fbb9c46aac1c8c5071b1a7f93bff96a1bcc7
[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" "c1630a38d30bd8d6bcd4267fcd24fbb9c46aac1c8c5071b1a7f93bff96a1bcc7", kill_on_drop: false }`
[INFO] [stderr]    Compiling bit_field v0.10.0
[INFO] [stderr]    Compiling riscv-target v0.1.2
[INFO] [stderr]    Compiling riscv v0.6.0 (https://github.com/rcore-os/riscv#21e32ee1)
[INFO] [stdout] error[E0554]: `#![feature]` may not be used on the stable release channel
[INFO] [stdout]   --> /opt/rustwide/cargo-home/git/checkouts/riscv-ab2abd16c438337b/21e32ee/src/lib.rs:17:37
[INFO] [stdout]    |
[INFO] [stdout] 17 | #![cfg_attr(feature = "inline-asm", feature(llvm_asm))]
[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 `riscv`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "c1630a38d30bd8d6bcd4267fcd24fbb9c46aac1c8c5071b1a7f93bff96a1bcc7", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c1630a38d30bd8d6bcd4267fcd24fbb9c46aac1c8c5071b1a7f93bff96a1bcc7", kill_on_drop: false }`
[INFO] [stdout] c1630a38d30bd8d6bcd4267fcd24fbb9c46aac1c8c5071b1a7f93bff96a1bcc7