[INFO] cloning repository https://github.com/matteocam/pay-to-sudoku-attack
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/matteocam/pay-to-sudoku-attack" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatteocam%2Fpay-to-sudoku-attack", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatteocam%2Fpay-to-sudoku-attack'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] cfc072fcdc17e10916185308edbdd232be808ad4
[INFO] building matteocam/pay-to-sudoku-attack against master#ff34b919075f35a1787659e9c448a34b06bab8de for issue-85264
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fmatteocam%2Fpay-to-sudoku-attack" "/workspace/builds/worker-12/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-12/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/matteocam/pay-to-sudoku-attack on toolchain ff34b919075f35a1787659e9c448a34b06bab8de
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ff34b919075f35a1787659e9c448a34b06bab8de" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/matteocam/pay-to-sudoku-attack
[INFO] finished tweaking git repo https://github.com/matteocam/pay-to-sudoku-attack
[INFO] tweaked toml for git repo https://github.com/matteocam/pay-to-sudoku-attack written to /workspace/builds/worker-12/source/Cargo.toml
[INFO] crate git repo https://github.com/matteocam/pay-to-sudoku-attack already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+ff34b919075f35a1787659e9c448a34b06bab8de" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded num-rational v0.1.36
[INFO] [stderr]   Downloaded mime v0.1.3
[INFO] [stderr]   Downloaded num-complex v0.1.37
[INFO] [stderr]   Downloaded rustc-serialize v0.3.23
[INFO] [stderr]   Downloaded hyper v0.6.16
[INFO] [stderr]   Downloaded fixedbitset v0.1.6
[INFO] [stderr]   Downloaded url v0.2.38
[INFO] [stderr]   Downloaded gcc v0.3.45
[INFO] [stderr]   Downloaded num-bigint v0.1.37
[INFO] [stderr]   Downloaded jsonrpc v0.7.6
[INFO] [stderr]   Downloaded whiteread v0.2.0
[INFO] [stderr]   Downloaded clap v1.5.6
[INFO] [stderr]   Downloaded strason v0.3.4
[INFO] [stderr]   Downloaded hex v0.1.0
[INFO] [stderr]   Downloaded bzip2 v0.2.4
[INFO] [stderr]   Downloaded bincode v0.4.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+ff34b919075f35a1787659e9c448a34b06bab8de" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 3946c30a475dc3db1112f8ac0be2ea33bbcb8308b9ef6fdb1807e461df7c3243
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "3946c30a475dc3db1112f8ac0be2ea33bbcb8308b9ef6fdb1807e461df7c3243", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "3946c30a475dc3db1112f8ac0be2ea33bbcb8308b9ef6fdb1807e461df7c3243", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "3946c30a475dc3db1112f8ac0be2ea33bbcb8308b9ef6fdb1807e461df7c3243", kill_on_drop: false }`
[INFO] [stdout] 3946c30a475dc3db1112f8ac0be2ea33bbcb8308b9ef6fdb1807e461df7c3243
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-12/source:/opt/rustwide/workdir:ro,Z" "-v" "/var/lib/crater-agent-workspace/cargo-home:/opt/rustwide/cargo-home:ro,Z" "-v" "/var/lib/crater-agent-workspace/rustup-home:/opt/rustwide/rustup-home:ro,Z" "-e" "SOURCE_DIR=/opt/rustwide/workdir" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=forbid" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--user" "0:0" "--network" "none" "ghcr.io/rust-lang/crates-build-env/linux@sha256:20528e8c29e4536546f0102ce88568b16ea7538393a33fcca951030f7af10457" "/opt/rustwide/cargo-home/bin/cargo" "+ff34b919075f35a1787659e9c448a34b06bab8de" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] aaf4a31fb0e33f5799a5796313089a4f3e3411a43716f1d9376976690b4f2893
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] running `Command { std: "docker" "start" "-a" "aaf4a31fb0e33f5799a5796313089a4f3e3411a43716f1d9376976690b4f2893", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] [stderr]    Compiling libc v0.2.21
[INFO] [stderr]    Compiling rustc-serialize v0.3.23
[INFO] [stderr]    Compiling num-traits v0.1.37
[INFO] [stderr]    Compiling gcc v0.3.45
[INFO] [stderr]    Compiling httparse v1.2.2
[INFO] [stderr]    Compiling strsim v0.4.1
[INFO] [stderr]    Compiling ansi_term v0.7.5
[INFO] [stderr]    Compiling vec_map v0.4.0
[INFO] [stderr]    Compiling bitflags v0.4.0
[INFO] [stderr]    Compiling hex v0.1.0
[INFO] [stderr]    Compiling thread-scoped v1.0.1
[INFO] [stderr]    Compiling whiteread v0.2.0
[INFO] [stderr]    Compiling fixedbitset v0.1.6
[INFO] [stderr]    Compiling hpack v0.2.0
[INFO] [stderr]    Compiling clap v1.5.6
[INFO] [stderr]    Compiling solicit v0.4.4
[INFO] [stderr]    Compiling rand v0.3.15
[INFO] [stderr]    Compiling time v0.1.36
[INFO] [stderr]    Compiling num_cpus v0.2.13
[INFO] [stderr]    Compiling num-integer v0.1.34
[INFO] [stderr]    Compiling miniz-sys v0.1.9
[INFO] [stderr]    Compiling bzip2-sys v0.1.5
[INFO] [stderr]    Compiling rust-crypto v0.2.36
[INFO] [stderr]    Compiling num-iter v0.1.33
[INFO] [stderr]    Compiling num-bigint v0.1.37
[INFO] [stderr]    Compiling num-complex v0.1.37
[INFO] [stderr]    Compiling uuid v0.1.18
[INFO] [stderr]    Compiling url v0.2.38
[INFO] [stderr]    Compiling flate2 v0.2.19
[INFO] [stderr]    Compiling num-rational v0.1.36
[INFO] [stderr]    Compiling bzip2 v0.2.4
[INFO] [stderr]    Compiling num v0.1.37
[INFO] [stderr]    Compiling serde v0.6.15
[INFO] [stderr]    Compiling cookie v0.1.21
[INFO] [stderr]    Compiling mime v0.1.3
[INFO] [stderr]    Compiling strason v0.3.4
[INFO] [stderr]    Compiling bincode v0.4.1
[INFO] [stderr]    Compiling hyper v0.6.16
[INFO] [stderr]    Compiling jsonrpc v0.7.6
[INFO] [stderr]    Compiling pay-to-sudoku v0.0.1 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused `#[macro_use]` import
[INFO] [stdout]   --> src/main.rs:15:1
[INFO] [stdout]    |
[INFO] [stdout] 15 | #[macro_use] extern crate jsonrpc;
[INFO] [stdout]    | ^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused imports: `Read`, `Write`, `self`
[INFO] [stdout]   --> src/main.rs:18:15
[INFO] [stdout]    |
[INFO] [stdout] 18 | use std::io::{self, Read, Write};
[INFO] [stdout]    |               ^^^^  ^^^^  ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `FromHex`
[INFO] [stdout]   --> src/main.rs:25:18
[INFO] [stdout]    |
[INFO] [stdout] 25 | use hex::{ToHex, FromHex};
[INFO] [stdout]    |                  ^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ffi.rs:54:32
[INFO] [stdout]    |
[INFO] [stdout] 54 |         let closure: &mut &mut for<'a> FnMut(&'a [u8], &'a [i8]) = mem::transmute(cb);
[INFO] [stdout]    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn for<'a> FnMut(&'a [u8], &'a [i8])`
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(bare_trait_objects)]` on by default
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ffi.rs:66:32
[INFO] [stdout]    |
[INFO] [stdout] 66 |         let closure: &mut &mut for<'a> FnMut(&'a [i8], &'a [i8]) = mem::transmute(cb);
[INFO] [stdout]    |                                ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn for<'a> FnMut(&'a [i8], &'a [i8])`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ffi.rs:73:22
[INFO] [stdout]    |
[INFO] [stdout] 73 |     let mut cb: &mut for<'a> FnMut(&'a [u8], &'a [u8]) = &mut f;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn for<'a> FnMut(&'a [u8], &'a [u8])`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]   --> src/ffi.rs:97:22
[INFO] [stdout]    |
[INFO] [stdout] 97 |     let mut cb: &mut for<'a> FnMut(&'a [u8], &'a [u8]) = &mut f;
[INFO] [stdout]    |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn for<'a> FnMut(&'a [u8], &'a [u8])`
[INFO] [stdout]    |
[INFO] [stdout]    = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]    = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: trait objects without an explicit `dyn` are deprecated
[INFO] [stdout]    --> src/ffi.rs:111:22
[INFO] [stdout]     |
[INFO] [stdout] 111 |     let mut cb: &mut for<'a> FnMut(&'a [u8], &'a [u8]) = &mut f;
[INFO] [stdout]     |                      ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: use `dyn`: `dyn for<'a> FnMut(&'a [u8], &'a [u8])`
[INFO] [stdout]     |
[INFO] [stdout]     = warning: this was previously accepted by the compiler but is being phased out; it will become a hard error in the 2021 edition!
[INFO] [stdout]     = note: for more information, see issue #80165 <https://github.com/rust-lang/rust/issues/80165>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `serde`
[INFO] [stdout]  --> src/bitcoin.rs:5:5
[INFO] [stdout]   |
[INFO] [stdout] 5 | use serde;
[INFO] [stdout]   |     ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `ToHex`
[INFO] [stdout]  --> src/bitcoin.rs:8:11
[INFO] [stdout]   |
[INFO] [stdout] 8 | use hex::{ToHex, FromHex};
[INFO] [stdout]   |           ^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/main.rs:194:5
[INFO] [stdout]     |
[INFO] [stdout] 194 |     try!(serialize_into(stream, &puzzle, Infinite));
[INFO] [stdout]     |     ^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/main.rs:198:28
[INFO] [stdout]     |
[INFO] [stdout] 198 |     let proof: Cow<[u8]> = try!(deserialize_from(stream, Infinite));
[INFO] [stdout]     |                            ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/main.rs:199:41
[INFO] [stdout]     |
[INFO] [stdout] 199 |     let encrypted_solution: Cow<[u8]> = try!(deserialize_from(stream, Infinite));
[INFO] [stdout]     |                                         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/main.rs:201:33
[INFO] [stdout]     |
[INFO] [stdout] 201 |     let mut h_of_key: Vec<u8> = try!(deserialize_from(stream, Infinite));
[INFO] [stdout]     |                                 ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/main.rs:214:9
[INFO] [stdout]     |
[INFO] [stdout] 214 |         try!(serialize_into(stream, &redeem_pubkey, Infinite));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/main.rs:215:9
[INFO] [stdout]     |
[INFO] [stdout] 215 |         try!(serialize_into(stream, &cltv_height, Infinite));
[INFO] [stdout]     |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/main.rs:217:38
[INFO] [stdout]     |
[INFO] [stdout] 217 |         let solving_pubkey: String = try!(deserialize_from(stream, Infinite));
[INFO] [stdout]     |                                      ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]    --> src/main.rs:311:28
[INFO] [stdout]     |
[INFO] [stdout] 311 |                         if (rx.lock().unwrap().try_recv().is_ok()) {
[INFO] [stdout]     |                            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `encrypted_solution`
[INFO] [stdout]    --> src/main.rs:179:16
[INFO] [stdout]     |
[INFO] [stdout] 179 |               |encrypted_solution, proof| {}));
[INFO] [stdout]     |                ^^^^^^^^^^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_encrypted_solution`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_variables)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `proof`
[INFO] [stdout]    --> src/main.rs:179:36
[INFO] [stdout]     |
[INFO] [stdout] 179 |               |encrypted_solution, proof| {}));
[INFO] [stdout]     |                                    ^^^^^ help: if this is intentional, prefix it with an underscore: `_proof`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/main.rs:352:13
[INFO] [stdout]     |
[INFO] [stdout] 352 |     fn from(a: bincode::serde::SerializeError) -> ProtoError {
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `a`
[INFO] [stdout]    --> src/main.rs:358:13
[INFO] [stdout]     |
[INFO] [stdout] 358 |     fn from(a: bincode::serde::DeserializeError) -> ProtoError {
[INFO] [stdout]     |             ^ help: if this is intentional, prefix it with an underscore: `_a`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `dimension`
[INFO] [stdout]   --> src/sudoku.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 15 |     fn new(dimension: usize) -> Possible {
[INFO] [stdout]    |            ^^^^^^^^^ help: if this is intentional, prefix it with an underscore: `_dimension`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `undo`
[INFO] [stdout]    --> src/sudoku.rs:218:21
[INFO] [stdout]     |
[INFO] [stdout] 218 |                 let undo = cell.set(candidate);
[INFO] [stdout]     |                     ^^^^ help: if this is intentional, prefix it with an underscore: `_undo`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `res`
[INFO] [stdout]   --> src/bitcoin.rs:54:9
[INFO] [stdout]    |
[INFO] [stdout] 54 |     let res = client.send_request(&request).unwrap();
[INFO] [stdout]    |         ^^^ help: if this is intentional, prefix it with an underscore: `_res`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `res`
[INFO] [stdout]    --> src/bitcoin.rs:146:9
[INFO] [stdout]     |
[INFO] [stdout] 146 |     let res = client.send_request(&request).unwrap();
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_res`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused variable: `res`
[INFO] [stdout]    --> src/bitcoin.rs:181:9
[INFO] [stdout]     |
[INFO] [stdout] 181 |     let res = client.send_request(&request).unwrap();
[INFO] [stdout]     |         ^^^ help: if this is intentional, prefix it with an underscore: `_res`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:201:9
[INFO] [stdout]     |
[INFO] [stdout] 201 |     let mut h_of_key: Vec<u8> = try!(deserialize_from(stream, Infinite));
[INFO] [stdout]     |         ----^^^^^^^^
[INFO] [stdout]     |         |
[INFO] [stdout]     |         help: remove this `mut`
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_mut)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:324:13
[INFO] [stdout]     |
[INFO] [stdout] 324 |         let mut txid;
[INFO] [stdout]     |             ----^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/main.rs:325:13
[INFO] [stdout]     |
[INFO] [stdout] 325 |         let mut vout;
[INFO] [stdout]     |             ----^^^^
[INFO] [stdout]     |             |
[INFO] [stdout]     |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/sudoku.rs:97:13
[INFO] [stdout]    |
[INFO] [stdout] 97 |         let mut grid = Sudoku::new(n);
[INFO] [stdout]    |             ----^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: associated function is never used: `print`
[INFO] [stdout]    --> src/sudoku.rs:164:12
[INFO] [stdout]     |
[INFO] [stdout] 164 |     pub fn print(&self) {
[INFO] [stdout]     |            ^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: function is never used: `get_sudoku_from_stdin`
[INFO] [stdout]   --> src/util.rs:33:8
[INFO] [stdout]    |
[INFO] [stdout] 33 | pub fn get_sudoku_from_stdin(dimension: usize) -> Vec<u8> {
[INFO] [stdout]    |        ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:117:9
[INFO] [stdout]     |
[INFO] [stdout] 117 |         handle_server(&mut stream, &ctx, n, &mut rpc);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `#[warn(unused_must_use)]` on by default
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:141:21
[INFO] [stdout]     |
[INFO] [stdout] 141 |                     handle_client(&mut stream, &ctx, n, &mut rpc);
[INFO] [stdout]     |                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:276:9
[INFO] [stdout]     |
[INFO] [stdout] 276 |         serialize_into(stream, &proof, Infinite);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:277:9
[INFO] [stdout]     |
[INFO] [stdout] 277 |         serialize_into(stream, &encrypted_solution, Infinite);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:278:9
[INFO] [stdout]     |
[INFO] [stdout] 278 |         serialize_into(stream, &h_of_key, Infinite);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:289:9
[INFO] [stdout]     |
[INFO] [stdout] 289 |         serialize_into(stream, &solving_pubkey, Infinite);
[INFO] [stdout]     |         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]    --> src/main.rs:318:17
[INFO] [stdout]     |
[INFO] [stdout] 318 |                 tx.send(());
[INFO] [stdout]     |                 ^^^^^^^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/sudoku.rs:88:9
[INFO] [stdout]    |
[INFO] [stdout] 88 |         grid.solve(&mut rng);
[INFO] [stdout]    |         ^^^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `extern` block uses type `Keypair`, which is not FFI-safe
[INFO] [stdout]   --> src/ffi.rs:24:12
[INFO] [stdout]    |
[INFO] [stdout] 24 |         -> *const Keypair;
[INFO] [stdout]    |            ^^^^^^^^^^^^^^ not FFI-safe
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(improper_ctypes)]` on by default
[INFO] [stdout]    = help: consider adding a member to this struct
[INFO] [stdout]    = note: this struct has no fields
[INFO] [stdout] note: the type is defined here
[INFO] [stdout]   --> src/ffi.rs:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | struct Keypair;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `extern` block uses type `Keypair`, which is not FFI-safe
[INFO] [stdout]   --> src/ffi.rs:25:27
[INFO] [stdout]    |
[INFO] [stdout] 25 |     fn gen_proof(keypair: *const Keypair, h: *mut c_void,
[INFO] [stdout]    |                           ^^^^^^^^^^^^^^ not FFI-safe
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider adding a member to this struct
[INFO] [stdout]    = note: this struct has no fields
[INFO] [stdout] note: the type is defined here
[INFO] [stdout]   --> src/ffi.rs:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | struct Keypair;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `extern` block uses type `Keypair`, which is not FFI-safe
[INFO] [stdout]   --> src/ffi.rs:30:40
[INFO] [stdout]    |
[INFO] [stdout] 30 |     fn malicious_snark_verify(keypair: *const Keypair,
[INFO] [stdout]    |                                        ^^^^^^^^^^^^^^ not FFI-safe
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider adding a member to this struct
[INFO] [stdout]    = note: this struct has no fields
[INFO] [stdout] note: the type is defined here
[INFO] [stdout]   --> src/ffi.rs:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | struct Keypair;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: `extern` block uses type `Keypair`, which is not FFI-safe
[INFO] [stdout]   --> src/ffi.rs:38:40
[INFO] [stdout]    |
[INFO] [stdout] 38 |     fn prove_malicious_verify(keypair: *const Keypair, h: *mut c_void,
[INFO] [stdout]    |                                        ^^^^^^^^^^^^^^ not FFI-safe
[INFO] [stdout]    |
[INFO] [stdout]    = help: consider adding a member to this struct
[INFO] [stdout]    = note: this struct has no fields
[INFO] [stdout] note: the type is defined here
[INFO] [stdout]   --> src/ffi.rs:11:1
[INFO] [stdout]    |
[INFO] [stdout] 11 | struct Keypair;
[INFO] [stdout]    | ^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused `Result` that must be used
[INFO] [stdout]   --> src/util.rs:64:17
[INFO] [stdout]    |
[INFO] [stdout] 64 |                 decoder.finish();
[INFO] [stdout]    |                 ^^^^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: this `Result` may be an `Err` variant, which should be handled
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: linking with `cc` failed: exit status: 1
[INFO] [stdout]   |
[INFO] [stdout]   = note: "cc" "-m64" "-Wl,--eh-frame-hdr" "-Wl,-znoexecstack" "-Wl,--as-needed" "-L" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.0.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.1.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.10.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.11.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.12.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.13.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.14.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.15.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.2.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.3.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.4.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.5.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.6.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.7.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.8.rcgu.o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.pay_to_sudoku.8z09u6cq-cgu.9.rcgu.o" "-o" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d" "/opt/rustwide/target/debug/deps/pay_to_sudoku-f13f7baba1e75f2d.42nvzxnrfm9vx5d9.rcgu.o" "-Wl,--gc-sections" "-pie" "-Wl,-zrelro" "-Wl,-znow" "-nodefaultlibs" "-L" "/opt/rustwide/target/debug/deps" "-L" "/opt/rustwide/target/debug/build/bzip2-sys-1779c2fc9f3948be/out" "-L" "/opt/rustwide/target/debug/build/miniz-sys-27b6954cde538945/out" "-L" "/opt/rustwide/target/debug/build/rust-crypto-1d547830be98cfe1/out" "-L" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib" "-lmysnark" "-Wl,-Bstatic" "/opt/rustwide/target/debug/deps/libjsonrpc-19edb7f93293453f.rlib" "/opt/rustwide/target/debug/deps/libhyper-302ae0c5a302af51.rlib" "/opt/rustwide/target/debug/deps/libmime-2cefa47125f936bb.rlib" "/opt/rustwide/target/debug/deps/liblanguage_tags-70ce019f1b650ec7.rlib" "/opt/rustwide/target/debug/deps/libsolicit-4e43350023f8769e.rlib" "/opt/rustwide/target/debug/deps/libhpack-d51fd093ce086e4b.rlib" "/opt/rustwide/target/debug/deps/liblog-8d5f4b48b2721cb0.rlib" "/opt/rustwide/target/debug/deps/libtypeable-dacfc48071ac3819.rlib" "/opt/rustwide/target/debug/deps/libtraitobject-7cb134996e77bf3b.rlib" "/opt/rustwide/target/debug/deps/libnum_cpus-16690f68f033df2b.rlib" "/opt/rustwide/target/debug/deps/libhttparse-f0fe99cf29442ad9.rlib" "/opt/rustwide/target/debug/deps/libunicase-6d58abadc769326e.rlib" "/opt/rustwide/target/debug/deps/libcookie-92377ef32de46566.rlib" "/opt/rustwide/target/debug/deps/liburl-f1b4f1a6404845ba.rlib" "/opt/rustwide/target/debug/deps/libmatches-d97c1a0708661dd6.rlib" "/opt/rustwide/target/debug/deps/libuuid-a369c73bdc18da91.rlib" "/opt/rustwide/target/debug/deps/libcrypto-3979de655b4ebf4c.rlib" "/opt/rustwide/target/debug/deps/libtime-e55a4d722697bf25.rlib" "/opt/rustwide/target/debug/deps/libstrason-3328555f21371200.rlib" "/opt/rustwide/target/debug/deps/libencoding-fe00f0f8d063dd53.rlib" "/opt/rustwide/target/debug/deps/libencoding_index_tradchinese-b3703bc050fd51d8.rlib" "/opt/rustwide/target/debug/deps/libencoding_index_simpchinese-2b17658a3bef67ba.rlib" "/opt/rustwide/target/debug/deps/libencoding_index_japanese-ceb7472a7b596cde.rlib" "/opt/rustwide/target/debug/deps/libencoding_index_korean-f0612366f8303ba0.rlib" "/opt/rustwide/target/debug/deps/libencoding_index_singlebyte-ff06d53920adc896.rlib" "/opt/rustwide/target/debug/deps/libflate2-bd1e889524a943aa.rlib" "/opt/rustwide/target/debug/deps/libminiz_sys-313e03b647e7fca8.rlib" "/opt/rustwide/target/debug/deps/libclap-51da97e75db1ffc3.rlib" "/opt/rustwide/target/debug/deps/libvec_map-f543c7d76302d402.rlib" "/opt/rustwide/target/debug/deps/libbitflags-3aed4555acd8ccfe.rlib" "/opt/rustwide/target/debug/deps/libansi_term-d3f9672e95771c8c.rlib" "/opt/rustwide/target/debug/deps/libstrsim-66a96aacdab0af00.rlib" "/opt/rustwide/target/debug/deps/libhex-d9eb0af5bb1f13c1.rlib" "/opt/rustwide/target/debug/deps/libthread_scoped-5e9d3e08b873f98e.rlib" "/opt/rustwide/target/debug/deps/libbincode-40fdeaaf46c5eae7.rlib" "/opt/rustwide/target/debug/deps/libserde-ed2c64bed291a366.rlib" "/opt/rustwide/target/debug/deps/libnum-62098e79cd9a1aac.rlib" "/opt/rustwide/target/debug/deps/libnum_rational-4845ef2f7e411a49.rlib" "/opt/rustwide/target/debug/deps/libnum_bigint-8d3e6843471e0ec4.rlib" "/opt/rustwide/target/debug/deps/librand-af99bdb345ae1afd.rlib" "/opt/rustwide/target/debug/deps/libnum_complex-bc2314b8268284ef.rlib" "/opt/rustwide/target/debug/deps/libnum_iter-945b1e4bcad6d1f2.rlib" "/opt/rustwide/target/debug/deps/libnum_integer-203aba52e977b2aa.rlib" "/opt/rustwide/target/debug/deps/libnum_traits-d28da72c707066c3.rlib" "/opt/rustwide/target/debug/deps/libbyteorder-1125042912305061.rlib" "/opt/rustwide/target/debug/deps/librustc_serialize-e75f6fdabba02db9.rlib" "/opt/rustwide/target/debug/deps/liblibc-87fe98f1240f2802.rlib" "/opt/rustwide/target/debug/deps/libwhiteread-7195306dbac67234.rlib" "-Wl,--start-group" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd-c6dddd3d354e6bea.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libpanic_unwind-c2ca47afdcc5e309.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libminiz_oxide-b47be2942017e108.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libadler-20a1e49116ab0df9.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libobject-25e09d9868291683.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libaddr2line-9c99fb6e5ca5159e.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libgimli-85040d7563599960.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libstd_detect-0e4f7587da8acf20.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_demangle-7be0a6711ed15b5c.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libhashbrown-00672fabc4ff9c9d.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_alloc-72fe231ef0473d15.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libunwind-019d54ecc304b655.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcfg_if-cc7d9343e4f608be.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/liblibc-e41c6d24baeb2249.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/liballoc-9849bb0fbad7f0f5.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/librustc_std_workspace_core-a1fd7734706d5518.rlib" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcore-c8ded1707ad10767.rlib" "-Wl,--end-group" "/opt/rustwide/rustup-home/toolchains/ff34b919075f35a1787659e9c448a34b06bab8de/lib/rustlib/x86_64-unknown-linux-gnu/lib/libcompiler_builtins-8b33f9cbbc9652fe.rlib" "-Wl,-Bdynamic" "-lutil" "-lgcc_s" "-lutil" "-lrt" "-lpthread" "-lm" "-ldl" "-lc"
[INFO] [stdout]   = note: /usr/bin/ld: cannot find -lmysnark
[INFO] [stdout]           collect2: error: ld returned 1 exit status
[INFO] [stdout]           
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: aborting due to previous error; 46 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `pay-to-sudoku`
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `Command { std: "docker" "inspect" "aaf4a31fb0e33f5799a5796313089a4f3e3411a43716f1d9376976690b4f2893", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aaf4a31fb0e33f5799a5796313089a4f3e3411a43716f1d9376976690b4f2893", kill_on_drop: false }`
[INFO] [stdout] aaf4a31fb0e33f5799a5796313089a4f3e3411a43716f1d9376976690b4f2893
