[INFO] cloning repository timmc/cavern
[INFO] running `"git" "clone" "--bare" "git://github.com/timmc/cavern.git" "work/cache/sources/gh/timmc/cavern"`
[INFO] [stderr] Cloning into bare repository 'work/cache/sources/gh/timmc/cavern'...
[INFO] running `"git" "clone" "work/cache/sources/gh/timmc/cavern" "work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/gh/timmc/cavern"`
[INFO] [stderr] Cloning into 'work/ex/pr-62008/sources/master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1/gh/timmc/cavern'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/timmc/cavern" "work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/timmc/cavern"`
[INFO] [stderr] Cloning into 'work/ex/pr-62008/sources/try#8f81d0bf6baf07b92f1246696722485c4ca0b049/gh/timmc/cavern'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 136368bae50e7f5f5a578663973139a6736cdc08
[INFO] sha for GitHub repo timmc/cavern: 136368bae50e7f5f5a578663973139a6736cdc08
[INFO] validating manifest of timmc/cavern on toolchain master#848e0a23f34aaab3e4a974b031c86ef2a4e4fcc1
[ERROR] this task or one of its parent failed!
[ERROR] overridden task result to broken:cargo-toml
[ERROR] caused by: missing Cargo.toml for timmc/cavern
[ERROR]