[INFO] updating cached repository timmc/cavern
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/timmc/cavern
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/timmc/cavern" "work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/timmc/cavern"`
[INFO] [stderr] Cloning into 'work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/gh/timmc/cavern'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/timmc/cavern" "work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/timmc/cavern"`
[INFO] [stderr] Cloning into 'work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/gh/timmc/cavern'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 66d7d176b1e4ed72d443f0d2a0e7e600edd1b038
[INFO] sha for GitHub repo timmc/cavern: 66d7d176b1e4ed72d443f0d2a0e7e600edd1b038
[INFO] validating manifest of timmc/cavern on toolchain master#f66e4697ae286985ddefc53c3a047614568458bb
[ERROR] this task or one of its parent failed!
[ERROR] overridden task result to build-fail:broken
[ERROR] caused by: missing Cargo.toml for timmc/cavern
[ERROR]