[INFO] crate monotone-cli 0.4.0 is already in cache
[INFO] extracting crate monotone-cli 0.4.0 into work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/reg/monotone-cli/0.4.0
[INFO] extracting crate monotone-cli 0.4.0 into work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/reg/monotone-cli/0.4.0
[INFO] validating manifest of monotone-cli-0.4.0 on toolchain master#f66e4697ae286985ddefc53c3a047614568458bb
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of monotone-cli-0.4.0 on toolchain try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c3b22200e6f5b70eb1f99ae6944d989ae17a458a-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing monotone-cli-0.4.0
[INFO] removed path dependency monotone from monotone-cli-0.4.0
[INFO] finished frobbing monotone-cli-0.4.0
[INFO] frobbed toml for monotone-cli-0.4.0 written to work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/reg/monotone-cli/0.4.0/Cargo.toml
[INFO] started frobbing monotone-cli-0.4.0
[INFO] removed path dependency monotone from monotone-cli-0.4.0
[INFO] finished frobbing monotone-cli-0.4.0
[INFO] frobbed toml for monotone-cli-0.4.0 written to work/ex/pr-58592/sources/try#c3b22200e6f5b70eb1f99ae6944d989ae17a458a/reg/monotone-cli/0.4.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr] error: failed to select a version for the requirement `ring = "^0.6"`
[INFO] [stderr]   candidate versions found which didn't match: 0.14.6, 0.14.5, 0.14.4, ...
[INFO] [stderr]   location searched: crates.io index
[INFO] [stderr] required by package `rusoto v0.23.0`
[INFO] [stderr]     ... which is depended on by `monotone-cli v0.4.0 (/mnt/big/crater/work/ex/pr-58592/sources/master#f66e4697ae286985ddefc53c3a047614568458bb/reg/monotone-cli/0.4.0)`
[ERROR] this task or one of its parent failed!
[ERROR] command `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+f66e4697ae286985ddefc53c3a047614568458bb-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"` failed