[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#f21fbac535ab2c3bc50db20547f4d48477357103 for pr-143193
[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 f21fbac535ab2c3bc50db20547f4d48477357103
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+f21fbac535ab2c3bc50db20547f4d48477357103" "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" "+f21fbac535ab2c3bc50db20547f4d48477357103" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded zero v0.1.2
[INFO] [stderr]   Downloaded font8x8 v0.2.5
[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

    Blocking waiting for file lock on package cache
    Updating crates.io index
    Blocking waiting for file lock on package cache
 Downloading crates ...
  Downloaded zero v0.1.2
  Downloaded font8x8 v0.2.5
  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.