[INFO] updating cached repository Moredread/mandelrust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/Moredread/mandelrust
[INFO] [stderr]  * branch              HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/Moredread/mandelrust" "work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/Moredread/mandelrust"`
[INFO] [stderr] Cloning into 'work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/Moredread/mandelrust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/Moredread/mandelrust" "work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/Moredread/mandelrust"`
[INFO] [stderr] Cloning into 'work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/Moredread/mandelrust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 9bd07eb40ff0267c1fb620f68b31a4c5f8d94c42
[INFO] sha for GitHub repo Moredread/mandelrust: 9bd07eb40ff0267c1fb620f68b31a4c5f8d94c42
[INFO] validating manifest of Moredread/mandelrust on toolchain master#60960a260f7b5c695fd0717311d72ce62dd4eb43
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of Moredread/mandelrust on toolchain try#266783e4e09e4e9d5307c1c8e695659c58bbcac7
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+266783e4e09e4e9d5307c1c8e695659c58bbcac7-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing Moredread/mandelrust
[INFO] finished frobbing Moredread/mandelrust
[INFO] frobbed toml for Moredread/mandelrust written to work/ex/pr-63376/sources/master#60960a260f7b5c695fd0717311d72ce62dd4eb43/gh/Moredread/mandelrust/Cargo.toml
[INFO] started frobbing Moredread/mandelrust
[INFO] finished frobbing Moredread/mandelrust
[INFO] frobbed toml for Moredread/mandelrust written to work/ex/pr-63376/sources/try#266783e4e09e4e9d5307c1c8e695659c58bbcac7/gh/Moredread/mandelrust/Cargo.toml
[INFO] crate Moredread/mandelrust already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Updating git repository `https://github.com/Moredread/rust-mpfr`
[INFO] [stderr] error: failed to load source for a dependency on `rust-mpfr`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   Unable to update https://github.com/Moredread/rust-mpfr?branch=wip#82aae977
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   failed to fetch into /mnt/big/crater/work/local/cargo-home/git/db/rust-mpfr-6e8daa21ec382474
[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" "+60960a260f7b5c695fd0717311d72ce62dd4eb43-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed