[INFO] updating cached repository nstoddard/rust-sand
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/nstoddard/rust-sand
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/nstoddard/rust-sand" "work/ex/beta-1.38-1/sources/1.37.0/gh/nstoddard/rust-sand"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/nstoddard/rust-sand'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/nstoddard/rust-sand" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nstoddard/rust-sand"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nstoddard/rust-sand'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] c1839a42c209f2cfa75679060509f58fca68173a
[INFO] sha for GitHub repo nstoddard/rust-sand: c1839a42c209f2cfa75679060509f58fca68173a
[INFO] validating manifest of nstoddard/rust-sand 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 nstoddard/rust-sand 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 nstoddard/rust-sand
[INFO] finished frobbing nstoddard/rust-sand
[INFO] frobbed toml for nstoddard/rust-sand written to work/ex/beta-1.38-1/sources/1.37.0/gh/nstoddard/rust-sand/Cargo.toml
[INFO] started frobbing nstoddard/rust-sand
[INFO] finished frobbing nstoddard/rust-sand
[INFO] frobbed toml for nstoddard/rust-sand written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/nstoddard/rust-sand/Cargo.toml
[INFO] crate nstoddard/rust-sand 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]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Updating git repository `https://github.com/nstoddard/gui-rs`
[INFO] [stderr] error: failed to load source for a dependency on `gui-rs`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   Unable to update https://github.com/nstoddard/gui-rs#f0ec857a
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   failed to fetch into /mnt/big/crater/work/local/cargo-home/git/db/gui-rs-79ace85c70810a81
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   failed to authenticate when downloading repository
[INFO] [stderr] attempted to find username/password via git's `credential.helper` support, but failed
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   failed to acquire username/password from local configuration
[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