[INFO] fetching crate mcl_derive 0.5.0-alpha...
[INFO] checking mcl_derive-0.5.0-alpha against master#fb4bca04fa1bde2f7db1b31a59e066f7bebd7fc6 for pr-120361
[INFO] extracting crate mcl_derive 0.5.0-alpha into /workspace/builds/worker-7-tc1/source
[INFO] validating manifest of crates.io crate mcl_derive 0.5.0-alpha on toolchain fb4bca04fa1bde2f7db1b31a59e066f7bebd7fc6
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+fb4bca04fa1bde2f7db1b31a59e066f7bebd7fc6" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate mcl_derive 0.5.0-alpha
[INFO] finished tweaking crates.io crate mcl_derive 0.5.0-alpha
[INFO] tweaked toml for crates.io crate mcl_derive 0.5.0-alpha written to /workspace/builds/worker-7-tc1/source/Cargo.toml
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+fb4bca04fa1bde2f7db1b31a59e066f7bebd7fc6" "generate-lockfile" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[ERROR] error running command: no output for 300 seconds
[ERROR] this task or one of its parent failed!
[ERROR] no output for 300 seconds
[ERROR] note: run with `RUST_BACKTRACE=1` to display a backtrace.