[INFO] updating cached repository quic-rs/quic
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/quic-rs/quic
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/quic-rs/quic" "work/ex/beta-1.38-1/sources/1.37.0/gh/quic-rs/quic"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/quic-rs/quic'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/quic-rs/quic" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/quic-rs/quic"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/quic-rs/quic'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 2e153bfe5d890ea68cb73b0c13b43f0260444cf8
[INFO] sha for GitHub repo quic-rs/quic: 2e153bfe5d890ea68cb73b0c13b43f0260444cf8
[INFO] validating manifest of quic-rs/quic 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 quic-rs/quic 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 quic-rs/quic
[INFO] finished frobbing quic-rs/quic
[INFO] frobbed toml for quic-rs/quic written to work/ex/beta-1.38-1/sources/1.37.0/gh/quic-rs/quic/Cargo.toml
[INFO] started frobbing quic-rs/quic
[INFO] finished frobbing quic-rs/quic
[INFO] frobbed toml for quic-rs/quic written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/quic-rs/quic/Cargo.toml
[INFO] crate quic-rs/quic 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]     Updating git repository `https://github.com/ctz/rustls`
[INFO] [stderr] error: failed to load source for a dependency on `rustls`
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   Unable to update https://github.com/ctz/rustls?branch=jbp-tls13-draft-28#40f60b57
[INFO] [stderr] 
[INFO] [stderr] Caused by:
[INFO] [stderr]   revspec '40f60b57756044ddac02dfa6049a8cfefad163f0' not found; class=Reference (4); code=NotFound (-3)
[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