[INFO] updating cached repository frxstrem/frxos2
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/frxstrem/frxos2
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/frxstrem/frxos2" "work/ex/beta-1.38-1/sources/1.37.0/gh/frxstrem/frxos2"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/frxstrem/frxos2'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/frxstrem/frxos2" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/frxstrem/frxos2"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/frxstrem/frxos2'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] be6ead192a672ab5be8f2d9097f865ae4aca55ea
[INFO] sha for GitHub repo frxstrem/frxos2: be6ead192a672ab5be8f2d9097f865ae4aca55ea
[INFO] validating manifest of frxstrem/frxos2 on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of frxstrem/frxos2 on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing frxstrem/frxos2
[INFO] removed workspace from frxstrem/frxos2
[INFO] finished frobbing frxstrem/frxos2
[INFO] frobbed toml for frxstrem/frxos2 written to work/ex/beta-1.38-1/sources/1.37.0/gh/frxstrem/frxos2/Cargo.toml
[INFO] started frobbing frxstrem/frxos2
[INFO] removed workspace from frxstrem/frxos2
[INFO] finished frobbing frxstrem/frxos2
[INFO] frobbed toml for frxstrem/frxos2 written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/frxstrem/frxos2/Cargo.toml
[INFO] crate frxstrem/frxos2 already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr] error: failed to download `bootloader v0.6.1`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   unable to get packages from source
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   failed to parse manifest at `/mnt/big/crater/work/local/cargo-home/registry/src/github.com-1ecc6299db9ec823/bootloader-0.6.1/Cargo.toml`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   the cargo feature `publish-lockfile` requires a nightly version of Cargo, but this is the `stable` channel
[INFO] [stderr] See https://doc.rust-lang.org/book/appendix-07-nightly-rust.html for more information about Rust release channels.
[ERROR] this task or one of its parent failed!
[ERROR] command `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed