[INFO] updating cached repository paul-hammant/merkle-rust
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/paul-hammant/merkle-rust
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/paul-hammant/merkle-rust" "work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/paul-hammant/merkle-rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/paul-hammant/merkle-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/paul-hammant/merkle-rust" "work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/paul-hammant/merkle-rust"`
[INFO] [stderr] Cloning into 'work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/paul-hammant/merkle-rust'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 02fe63b8d4224c79266d9bcd0192f9a7a8698e1a
[INFO] sha for GitHub repo paul-hammant/merkle-rust: 02fe63b8d4224c79266d9bcd0192f9a7a8698e1a
[INFO] validating manifest of paul-hammant/merkle-rust on toolchain master#39401465da4ce27aeeb2c2a26133ac35c63aa515
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of paul-hammant/merkle-rust on toolchain try#f45cc3094ee337acd688771b9234318046b0572d
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing paul-hammant/merkle-rust
[INFO] finished frobbing paul-hammant/merkle-rust
[INFO] frobbed toml for paul-hammant/merkle-rust written to work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/paul-hammant/merkle-rust/Cargo.toml
[INFO] started frobbing paul-hammant/merkle-rust
[INFO] finished frobbing paul-hammant/merkle-rust
[INFO] frobbed toml for paul-hammant/merkle-rust written to work/ex/pr-60914/sources/try#f45cc3094ee337acd688771b9234318046b0572d/gh/paul-hammant/merkle-rust/Cargo.toml
[INFO] crate paul-hammant/merkle-rust already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr] error: the lock file /mnt/crater-raid/crater/work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/paul-hammant/merkle-rust/Cargo.lock needs to be updated but --locked was passed to prevent this
[INFO] the lockfile is outdated, regenerating it
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/crater-raid/crater/work/local/cargo-home/bin/cargo" "+f45cc3094ee337acd688771b9234318046b0572d-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking paul-hammant/merkle-rust against master#39401465da4ce27aeeb2c2a26133ac35c63aa515 for pr-60914
[INFO] running `"docker" "create" "-v" "/mnt/crater-raid/crater/work/local/target-dirs/pr-60914/worker-7/master#39401465da4ce27aeeb2c2a26133ac35c63aa515:/opt/crater/target:rw,Z" "-v" "/mnt/crater-raid/crater/work/ex/pr-60914/sources/master#39401465da4ce27aeeb2c2a26133ac35c63aa515/gh/paul-hammant/merkle-rust:/opt/crater/workdir:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/crater-raid/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+39401465da4ce27aeeb2c2a26133ac35c63aa515-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 354305d7df4b82f641ddf32d0562d747e3142343bd6b9068fbe406c0c33c65de
[INFO] running `"docker" "start" "-a" "354305d7df4b82f641ddf32d0562d747e3142343bd6b9068fbe406c0c33c65de"`
[INFO] [stderr]     Checking glob v0.3.0
[INFO] [stderr]     Checking inotify-sys v0.1.3
[INFO] [stderr]     Checking mio-extras v2.0.5
[INFO] [stderr]     Checking inotify v0.6.1
[INFO] [stderr]     Checking notify v4.0.11
[INFO] [stderr]     Checking simple_merkle_tree_demo v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `std::sync::Mutex`
[INFO] [stderr]   --> src/server.rs:29:5
[INFO] [stderr]    |
[INFO] [stderr] 29 | use std::sync::Mutex;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `std::sync::Mutex`
[INFO] [stderr]   --> src/server.rs:29:5
[INFO] [stderr]    |
[INFO] [stderr] 29 | use std::sync::Mutex;
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_imports)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `why`
[INFO] [stderr]   --> src/server.rs:88:21
[INFO] [stderr]    |
[INFO] [stderr] 88 |                 Err(why) => {
[INFO] [stderr]    |                     ^^^ help: consider prefixing with an underscore: `_why`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unused variable: `why`
[INFO] [stderr]   --> src/server.rs:88:21
[INFO] [stderr]    |
[INFO] [stderr] 88 |                 Err(why) => {
[INFO] [stderr]    |                     ^^^ help: consider prefixing with an underscore: `_why`
[INFO] [stderr]    |
[INFO] [stderr]    = note: #[warn(unused_variables)] on by default
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 2.87s
[INFO] running `"docker" "inspect" "354305d7df4b82f641ddf32d0562d747e3142343bd6b9068fbe406c0c33c65de"`
[INFO] running `"docker" "rm" "-f" "354305d7df4b82f641ddf32d0562d747e3142343bd6b9068fbe406c0c33c65de"`
[INFO] [stdout] 354305d7df4b82f641ddf32d0562d747e3142343bd6b9068fbe406c0c33c65de