[INFO] updating cached repository PEshwar/toy_blockchain
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/PEshwar/toy_blockchain
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/PEshwar/toy_blockchain" "work/ex/pr-63565/sources/master#c43d03a19f326f4a323569328cc501e86eb6d22e/gh/PEshwar/toy_blockchain"`
[INFO] [stderr] Cloning into 'work/ex/pr-63565/sources/master#c43d03a19f326f4a323569328cc501e86eb6d22e/gh/PEshwar/toy_blockchain'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/PEshwar/toy_blockchain" "work/ex/pr-63565/sources/try#75eff020d0923c035c2fe220db4a0465cd847048/gh/PEshwar/toy_blockchain"`
[INFO] [stderr] Cloning into 'work/ex/pr-63565/sources/try#75eff020d0923c035c2fe220db4a0465cd847048/gh/PEshwar/toy_blockchain'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] c3f9d29fea64ac54da7ebb46da5a04e995585d22
[INFO] sha for GitHub repo PEshwar/toy_blockchain: c3f9d29fea64ac54da7ebb46da5a04e995585d22
[INFO] validating manifest of PEshwar/toy_blockchain on toolchain master#c43d03a19f326f4a323569328cc501e86eb6d22e
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c43d03a19f326f4a323569328cc501e86eb6d22e-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of PEshwar/toy_blockchain on toolchain try#75eff020d0923c035c2fe220db4a0465cd847048
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+75eff020d0923c035c2fe220db4a0465cd847048-alt" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing PEshwar/toy_blockchain
[INFO] finished frobbing PEshwar/toy_blockchain
[INFO] frobbed toml for PEshwar/toy_blockchain written to work/ex/pr-63565/sources/master#c43d03a19f326f4a323569328cc501e86eb6d22e/gh/PEshwar/toy_blockchain/Cargo.toml
[INFO] started frobbing PEshwar/toy_blockchain
[INFO] finished frobbing PEshwar/toy_blockchain
[INFO] frobbed toml for PEshwar/toy_blockchain written to work/ex/pr-63565/sources/try#75eff020d0923c035c2fe220db4a0465cd847048/gh/PEshwar/toy_blockchain/Cargo.toml
[INFO] crate PEshwar/toy_blockchain already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+c43d03a19f326f4a323569328cc501e86eb6d22e-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+75eff020d0923c035c2fe220db4a0465cd847048-alt" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] checking PEshwar/toy_blockchain against master#c43d03a19f326f4a323569328cc501e86eb6d22e for pr-63565
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/pr-63565/worker-4/master#c43d03a19f326f4a323569328cc501e86eb6d22e:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/pr-63565/sources/master#c43d03a19f326f4a323569328cc501e86eb6d22e/gh/PEshwar/toy_blockchain:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/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" "+c43d03a19f326f4a323569328cc501e86eb6d22e-alt" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stdout] 9ce3ab14449a77eed64569c03dddc93329397cf2cbc5676b7a3f124f2ee8defe
[INFO] running `"docker" "start" "-a" "9ce3ab14449a77eed64569c03dddc93329397cf2cbc5676b7a3f124f2ee8defe"`
[INFO] [stderr]     Checking openssl-sys v0.9.47
[INFO] [stderr]     Checking serde v1.0.94
[INFO] [stderr]     Checking openssl v0.10.23
[INFO] [stderr]     Checking crypto-hash v0.3.3
[INFO] [stderr]     Checking serde_json v1.0.40
[INFO] [stderr]     Checking peblock v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/main.rs:35:5
[INFO] [stderr]    |
[INFO] [stderr] 35 |     pub fn new(timestamp: u64, transactions: Vec<Transaction>, previous_block: &Block) -> Block {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `genesis`
[INFO] [stderr]   --> src/main.rs:46:5
[INFO] [stderr]    |
[INFO] [stderr] 46 |     pub fn genesis() -> Block {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `to_json`
[INFO] [stderr]   --> src/main.rs:60:5
[INFO] [stderr]    |
[INFO] [stderr] 60 |     pub fn to_json(&self) -> String {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `hash`
[INFO] [stderr]   --> src/main.rs:64:5
[INFO] [stderr]    |
[INFO] [stderr] 64 |     pub fn hash(block: &Block) -> String {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `is_valid`
[INFO] [stderr]   --> src/main.rs:68:5
[INFO] [stderr]    |
[INFO] [stderr] 68 |     pub fn is_valid(hash: &str, prefix: &str) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `mine_next_block`
[INFO] [stderr]   --> src/main.rs:71:5
[INFO] [stderr]    |
[INFO] [stderr] 71 |     fn mine_next_block(candidate_block: &mut Block, prefix: &str)  {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Blockchain`
[INFO] [stderr]   --> src/main.rs:80:1
[INFO] [stderr]    |
[INFO] [stderr] 80 | struct Blockchain {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]   --> src/main.rs:35:5
[INFO] [stderr]    |
[INFO] [stderr] 35 |     pub fn new(timestamp: u64, transactions: Vec<Transaction>, previous_block: &Block) -> Block {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `genesis`
[INFO] [stderr]   --> src/main.rs:46:5
[INFO] [stderr]    |
[INFO] [stderr] 46 |     pub fn genesis() -> Block {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `to_json`
[INFO] [stderr]   --> src/main.rs:60:5
[INFO] [stderr]    |
[INFO] [stderr] 60 |     pub fn to_json(&self) -> String {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `hash`
[INFO] [stderr]   --> src/main.rs:64:5
[INFO] [stderr]    |
[INFO] [stderr] 64 |     pub fn hash(block: &Block) -> String {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `is_valid`
[INFO] [stderr]   --> src/main.rs:68:5
[INFO] [stderr]    |
[INFO] [stderr] 68 |     pub fn is_valid(hash: &str, prefix: &str) -> bool {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `mine_next_block`
[INFO] [stderr]   --> src/main.rs:71:5
[INFO] [stderr]    |
[INFO] [stderr] 71 |     fn mine_next_block(candidate_block: &mut Block, prefix: &str)  {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Blockchain`
[INFO] [stderr]   --> src/main.rs:80:1
[INFO] [stderr]    |
[INFO] [stderr] 80 | struct Blockchain {
[INFO] [stderr]    | ^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 16.63s
[INFO] running `"docker" "inspect" "9ce3ab14449a77eed64569c03dddc93329397cf2cbc5676b7a3f124f2ee8defe"`
[INFO] running `"docker" "rm" "-f" "9ce3ab14449a77eed64569c03dddc93329397cf2cbc5676b7a3f124f2ee8defe"`
[INFO] [stdout] 9ce3ab14449a77eed64569c03dddc93329397cf2cbc5676b7a3f124f2ee8defe