[INFO] cloning repository https://github.com/willgorman/rust-os-book-walkthrough
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/willgorman/rust-os-book-walkthrough" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwillgorman%2Frust-os-book-walkthrough", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwillgorman%2Frust-os-book-walkthrough'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 693cd4916327e8f297fb72d1571f90b34763fc9c
[INFO] checking willgorman/rust-os-book-walkthrough against master#04ff05c9c0cfbca33115c5f1b8bb20a66a54b799 for pr-147834
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fwillgorman%2Frust-os-book-walkthrough" "/workspace/builds/worker-4-tc1/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4-tc1/source'...
[INFO] [stderr] done.
[INFO] removed /workspace/builds/worker-4-tc1/source/.cargo/config
[INFO] started tweaking git repo https://github.com/willgorman/rust-os-book-walkthrough
[INFO] finished tweaking git repo https://github.com/willgorman/rust-os-book-walkthrough
[INFO] tweaked toml for git repo https://github.com/willgorman/rust-os-book-walkthrough written to /workspace/builds/worker-4-tc1/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/willgorman/rust-os-book-walkthrough on toolchain 04ff05c9c0cfbca33115c5f1b8bb20a66a54b799
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+04ff05c9c0cfbca33115c5f1b8bb20a66a54b799" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/willgorman/rust-os-book-walkthrough already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+04ff05c9c0cfbca33115c5f1b8bb20a66a54b799" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded llvm-tools v0.1.1
[INFO] [stderr]   Downloaded usize_conversions v0.2.0
[INFO] [stderr]   Downloaded bit_field v0.9.0
[INFO] [stderr]   Downloaded os_bootinfo v0.2.1
[INFO] [stderr]   Downloaded array-init v0.0.4
[INFO] [stderr]   Downloaded bootloader v0.6.0
[INFO] [stderr] error: failed to parse manifest at `/workspace/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/bootloader-0.6.0/Cargo.toml`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   the cargo feature `publish-lockfile` has been removed in the 1.37 release
[INFO] [stderr] 
[INFO] [stderr]   This package cannot be used with this version of Cargo, as the unstable feature `publish-lockfile` is no longer supported.
[INFO] [stderr]   See https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#publish-lockfile for more information about using this feature.


command failed: exit status: 101

    Updating crates.io index
 Downloading crates ...
  Downloaded llvm-tools v0.1.1
  Downloaded usize_conversions v0.2.0
  Downloaded bit_field v0.9.0
  Downloaded os_bootinfo v0.2.1
  Downloaded array-init v0.0.4
  Downloaded bootloader v0.6.0
error: failed to parse manifest at `/workspace/cargo-home/registry/src/index.crates.io-1949cf8c6b5b557f/bootloader-0.6.0/Cargo.toml`

Caused by:
  the cargo feature `publish-lockfile` has been removed in the 1.37 release

  This package cannot be used with this version of Cargo, as the unstable feature `publish-lockfile` is no longer supported.
  See https://doc.rust-lang.org/nightly/cargo/reference/unstable.html#publish-lockfile for more information about using this feature.