[INFO] updating cached repository https://github.com/rust-lang-nursery/rustup.rs
[INFO] running `"git" "-c" "credential.helper=" "-c" "credential.helper=/mnt/big/crater/work/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune"`
[INFO] [stderr] From https://github.com/rust-lang-nursery/rustup.rs
[INFO] [stderr]    c6ff944b..ec6d1afc  master     -> master
[INFO] [stderr]  * [new tag]           1.19.0     -> 1.19.0
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] ec6d1afcbe0fe2f0f52fb7b856f9672ebf87b177
[ERROR] this task or one of its parent failed!
[ERROR] command `"/mnt/big/crater/work/cargo-home/bin/cargo" "+e689e5eaefe96e6dc3ed5bb629c521b7d207aff7-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"` failed