[INFO] updating cached repository robbystk/rust-by-the-book
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/robbystk/rust-by-the-book
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/robbystk/rust-by-the-book" "work/ex/pr-62849/sources/master#435236b8877cdb98c82eaebfb7887782277265c5/gh/robbystk/rust-by-the-book"`
[INFO] [stderr] Cloning into 'work/ex/pr-62849/sources/master#435236b8877cdb98c82eaebfb7887782277265c5/gh/robbystk/rust-by-the-book'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/robbystk/rust-by-the-book" "work/ex/pr-62849/sources/try#b5c7f157c20453dde8d47371abe73b32351b4e7f/gh/robbystk/rust-by-the-book"`
[INFO] [stderr] Cloning into 'work/ex/pr-62849/sources/try#b5c7f157c20453dde8d47371abe73b32351b4e7f/gh/robbystk/rust-by-the-book'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] b7b31e5df56131e49ded651ae19906ad0443a5e5
[INFO] sha for GitHub repo robbystk/rust-by-the-book: b7b31e5df56131e49ded651ae19906ad0443a5e5
[INFO] validating manifest of robbystk/rust-by-the-book on toolchain master#435236b8877cdb98c82eaebfb7887782277265c5
[ERROR] this task or one of its parent failed!
[ERROR] overridden task result to broken:cargo-toml
[ERROR] caused by: missing Cargo.toml for robbystk/rust-by-the-book
[ERROR]