[INFO] updating cached repository 3goliad/castel
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/3goliad/castel
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/3goliad/castel" "work/ex/pr-60620-1/sources/master#ef01f29964df207f181bd5bcf236e41372a17273/gh/3goliad/castel"`
[INFO] [stderr] Cloning into 'work/ex/pr-60620-1/sources/master#ef01f29964df207f181bd5bcf236e41372a17273/gh/3goliad/castel'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/3goliad/castel" "work/ex/pr-60620-1/sources/try#a7cff45e655f886da150e206c7acbe984df4ab71/gh/3goliad/castel"`
[INFO] [stderr] Cloning into 'work/ex/pr-60620-1/sources/try#a7cff45e655f886da150e206c7acbe984df4ab71/gh/3goliad/castel'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 3c93ed52ad98c6ceaa5d17c0fd61d2c21a77032c
[INFO] sha for GitHub repo 3goliad/castel: 3c93ed52ad98c6ceaa5d17c0fd61d2c21a77032c
[INFO] validating manifest of 3goliad/castel on toolchain master#ef01f29964df207f181bd5bcf236e41372a17273
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+ef01f29964df207f181bd5bcf236e41372a17273-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of 3goliad/castel on toolchain try#a7cff45e655f886da150e206c7acbe984df4ab71
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+a7cff45e655f886da150e206c7acbe984df4ab71-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing 3goliad/castel
[INFO] finished frobbing 3goliad/castel
[INFO] frobbed toml for 3goliad/castel written to work/ex/pr-60620-1/sources/master#ef01f29964df207f181bd5bcf236e41372a17273/gh/3goliad/castel/Cargo.toml
[INFO] started frobbing 3goliad/castel
[INFO] finished frobbing 3goliad/castel
[INFO] frobbed toml for 3goliad/castel written to work/ex/pr-60620-1/sources/try#a7cff45e655f886da150e206c7acbe984df4ab71/gh/3goliad/castel/Cargo.toml
[INFO] crate 3goliad/castel already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+ef01f29964df207f181bd5bcf236e41372a17273-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Updating git repository `https://github.com/mozilla/mentat`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr] error: failed to select a version for `backtrace`.
[INFO] [stderr]     ... required by package `failure v0.1.1`
[INFO] [stderr]     ... which is depended on by `mentat v0.11.1 (https://github.com/mozilla/mentat#e55376e9)`
[INFO] [stderr]     ... which is depended on by `castel v0.1.0 (/mnt/big/crater/work/ex/pr-60620-1/sources/master#ef01f29964df207f181bd5bcf236e41372a17273/gh/3goliad/castel)`
[INFO] [stderr] versions that meet the requirements `^0.3.3` are: 0.3.15, 0.3.14, 0.3.13, 0.3.12, 0.3.11, 0.3.9, 0.3.8, 0.3.7, 0.3.6, 0.3.5, 0.3.4, 0.3.3
[INFO] [stderr] 
[INFO] [stderr] all possible versions conflict with previously selected packages.
[INFO] [stderr] 
[INFO] [stderr]   previously selected package `backtrace v0.3.2`
[INFO] [stderr]     ... which is depended on by `error-chain v0.10.0`
[INFO] [stderr]     ... which is depended on by `castel v0.1.0 (/mnt/big/crater/work/ex/pr-60620-1/sources/master#ef01f29964df207f181bd5bcf236e41372a17273/gh/3goliad/castel)`
[INFO] [stderr] 
[INFO] [stderr] failed to select a version for `backtrace` which could resolve this conflict
[ERROR] this task or one of its parent failed!
[ERROR] command `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+ef01f29964df207f181bd5bcf236e41372a17273-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed