[INFO] crate muxrpc 0.3.0 is already in cache
[INFO] extracting crate muxrpc 0.3.0 into work/ex/pr-56955/sources/master#d99a320cba42f661aebfa1293b7b2ec3603dda75/reg/muxrpc/0.3.0
[INFO] extracting crate muxrpc 0.3.0 into work/ex/pr-56955/sources/try#e70472fc501b855c9080f3772432c10fe20b8866/reg/muxrpc/0.3.0
[INFO] validating manifest of muxrpc-0.3.0 on toolchain master#d99a320cba42f661aebfa1293b7b2ec3603dda75
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+d99a320cba42f661aebfa1293b7b2ec3603dda75-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of muxrpc-0.3.0 on toolchain try#e70472fc501b855c9080f3772432c10fe20b8866
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+e70472fc501b855c9080f3772432c10fe20b8866-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing muxrpc-0.3.0
[INFO] finished frobbing muxrpc-0.3.0
[INFO] frobbed toml for muxrpc-0.3.0 written to work/ex/pr-56955/sources/master#d99a320cba42f661aebfa1293b7b2ec3603dda75/reg/muxrpc/0.3.0/Cargo.toml
[INFO] started frobbing muxrpc-0.3.0
[INFO] finished frobbing muxrpc-0.3.0
[INFO] frobbed toml for muxrpc-0.3.0 written to work/ex/pr-56955/sources/try#e70472fc501b855c9080f3772432c10fe20b8866/reg/muxrpc/0.3.0/Cargo.toml
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+d99a320cba42f661aebfa1293b7b2ec3603dda75-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] [stderr] error: failed to select a version for the requirement `futures = "^0.2.0-alpha"`
[INFO] [stderr]   candidate versions found which didn't match: 0.1.25, 0.1.24, 0.1.23, ...
[INFO] [stderr]   location searched: crates.io index
[INFO] [stderr] required by package `muxrpc v0.3.0 (/mnt/big/crater/work/ex/pr-56955/sources/master#d99a320cba42f661aebfa1293b7b2ec3603dda75/reg/muxrpc/0.3.0)`
[ERROR] this task or one of its parent failed!
[ERROR] command `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+d99a320cba42f661aebfa1293b7b2ec3603dda75-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"` failed