[INFO] updating cached repository https://github.com/Sherif-Abdou/basic-algebra
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "-c" "remote.origin.fetch=refs/heads/*:refs/heads/*" "fetch" "origin" "--force" "--prune", kill_on_drop: false }`
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 68f7850565c1d8a03512daa152434c4333c93b4a
[INFO] testing Sherif-Abdou/basic-algebra against beta-2020-07-24 for beta-1.46-1
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2FSherif-Abdou%2Fbasic-algebra" "/workspace/builds/worker-9/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-9/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/Sherif-Abdou/basic-algebra on toolchain beta-2020-07-24
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "read-manifest" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] started tweaking git repo https://github.com/Sherif-Abdou/basic-algebra
[INFO] finished tweaking git repo https://github.com/Sherif-Abdou/basic-algebra
[INFO] tweaked toml for git repo https://github.com/Sherif-Abdou/basic-algebra written to /workspace/builds/worker-9/source/Cargo.toml
[INFO] crate git repo https://github.com/Sherif-Abdou/basic-algebra already has a lockfile, it will not be regenerated
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+beta-2020-07-24" "fetch" "--locked" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-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" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 1cda26e980aa92192ff2738065ee5b13f7b73dfc48d75809d0393c10a923f506
[INFO] running `Command { std: "docker" "start" "-a" "1cda26e980aa92192ff2738065ee5b13f7b73dfc48d75809d0393c10a923f506", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "1cda26e980aa92192ff2738065ee5b13f7b73dfc48d75809d0393c10a923f506", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "1cda26e980aa92192ff2738065ee5b13f7b73dfc48d75809d0393c10a923f506", kill_on_drop: false }`
[INFO] [stdout] 1cda26e980aa92192ff2738065ee5b13f7b73dfc48d75809d0393c10a923f506
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] b67ce8acb40664a8c82d54ad1f4a53ef0f2e7c4f8b1011238e2fda22266636f2
[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" "b67ce8acb40664a8c82d54ad1f4a53ef0f2e7c4f8b1011238e2fda22266636f2", kill_on_drop: false }`
[INFO] [stderr]    Compiling memchr v2.3.3
[INFO] [stderr]    Compiling regex-syntax v0.6.18
[INFO] [stderr]    Compiling aho-corasick v0.7.10
[INFO] [stderr]    Compiling regex v1.3.9
[INFO] [stderr]    Compiling algebra v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/equation_solver.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/equation_solver.rs:77:32
[INFO] [stdout]    |
[INFO] [stdout] 77 |         let new_left_side = if (!flip) {
[INFO] [stdout]    |                                ^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]    --> src/equation_solver.rs:101:19
[INFO] [stdout]     |
[INFO] [stdout] 101 |         return if (!flip) {
[INFO] [stdout]     |                   ^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::equation::*`
[INFO] [stdout]  --> src/main.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use crate::equation::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:50:26
[INFO] [stdout]    |
[INFO] [stdout] 50 |             let values = (*box_tuple.clone());
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:58:26
[INFO] [stdout]    |
[INFO] [stdout] 58 |             let values = (*box_tuple.clone());
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:66:26
[INFO] [stdout]    |
[INFO] [stdout] 66 |             let values = (*box_tuple.clone());
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:74:26
[INFO] [stdout]    |
[INFO] [stdout] 74 |             let values = (*box_tuple.clone());
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let mut new_eq_result = solver.solve_step();
[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:102:13
[INFO] [stdout]     |
[INFO] [stdout] 102 |         let mut equation = equation::Equation::from_tokens(tokens);
[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:108:13
[INFO] [stdout]     |
[INFO] [stdout] 108 |         let mut solver =
[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/equation_solver.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let mut variable_path = self.get_variable_path()?;
[INFO] [stdout]    |             ----^^^^^^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 19.06s
[INFO] running `Command { std: "docker" "inspect" "b67ce8acb40664a8c82d54ad1f4a53ef0f2e7c4f8b1011238e2fda22266636f2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "b67ce8acb40664a8c82d54ad1f4a53ef0f2e7c4f8b1011238e2fda22266636f2", kill_on_drop: false }`
[INFO] [stdout] b67ce8acb40664a8c82d54ad1f4a53ef0f2e7c4f8b1011238e2fda22266636f2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 6ec683f56279bbf2cf61eca088e719fec391a9030052edf64fd95bdaf5f609a5
[INFO] running `Command { std: "docker" "start" "-a" "6ec683f56279bbf2cf61eca088e719fec391a9030052edf64fd95bdaf5f609a5", kill_on_drop: false }`
[INFO] [stderr]    Compiling algebra v0.1.0 (/opt/rustwide/workdir)
[INFO] [stdout] warning: unused import: `std::borrow::Borrow`
[INFO] [stdout]  --> src/equation_solver.rs:2:5
[INFO] [stdout]   |
[INFO] [stdout] 2 | use std::borrow::Borrow;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stdout]   |
[INFO] [stdout]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]   --> src/equation_solver.rs:77:32
[INFO] [stdout]    |
[INFO] [stdout] 77 |         let new_left_side = if (!flip) {
[INFO] [stdout]    |                                ^^^^^^^ help: remove these parentheses
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around `if` condition
[INFO] [stdout]    --> src/equation_solver.rs:101:19
[INFO] [stdout]     |
[INFO] [stdout] 101 |         return if (!flip) {
[INFO] [stdout]     |                   ^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unused import: `crate::equation::*`
[INFO] [stdout]  --> src/main.rs:7:5
[INFO] [stdout]   |
[INFO] [stdout] 7 | use crate::equation::*;
[INFO] [stdout]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:50:26
[INFO] [stdout]    |
[INFO] [stdout] 50 |             let values = (*box_tuple.clone());
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:58:26
[INFO] [stdout]    |
[INFO] [stdout] 58 |             let values = (*box_tuple.clone());
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:66:26
[INFO] [stdout]    |
[INFO] [stdout] 66 |             let values = (*box_tuple.clone());
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: unnecessary parentheses around assigned value
[INFO] [stdout]   --> src/main.rs:74:26
[INFO] [stdout]    |
[INFO] [stdout] 74 |             let values = (*box_tuple.clone());
[INFO] [stdout]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]   --> src/main.rs:37:9
[INFO] [stdout]    |
[INFO] [stdout] 37 |     let mut new_eq_result = solver.solve_step();
[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:102:13
[INFO] [stdout]     |
[INFO] [stdout] 102 |         let mut equation = equation::Equation::from_tokens(tokens);
[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:108:13
[INFO] [stdout]     |
[INFO] [stdout] 108 |         let mut solver =
[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/equation_solver.rs:19:13
[INFO] [stdout]    |
[INFO] [stdout] 19 |         let mut variable_path = self.get_variable_path()?;
[INFO] [stdout]    |             ----^^^^^^^^^^^^^
[INFO] [stdout]    |             |
[INFO] [stdout]    |             help: remove this `mut`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 12 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.85s
[INFO] running `Command { std: "docker" "inspect" "6ec683f56279bbf2cf61eca088e719fec391a9030052edf64fd95bdaf5f609a5", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6ec683f56279bbf2cf61eca088e719fec391a9030052edf64fd95bdaf5f609a5", kill_on_drop: false }`
[INFO] [stdout] 6ec683f56279bbf2cf61eca088e719fec391a9030052edf64fd95bdaf5f609a5
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-9/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" "MAP_USER_ID=0" "-e" "CARGO_TARGET_DIR=/opt/rustwide/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/rustwide/cargo-home" "-e" "RUSTUP_HOME=/opt/rustwide/rustup-home" "-w" "/opt/rustwide/workdir" "-m" "1610612736" "--network" "none" "rustops/crates-build-env@sha256:a636fd89d022f18117e1dc8fb37a0a009933cdbbe082814857f0e2024962d47c" "/opt/rustwide/cargo-home/bin/cargo" "+beta-2020-07-24" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 4f11b35f76d7e06ff3bc169baadec173c03feae823a50839a2230826970daf01
[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" "4f11b35f76d7e06ff3bc169baadec173c03feae823a50839a2230826970daf01", kill_on_drop: false }`
[INFO] [stderr] warning: unused import: `std::borrow::Borrow`
[INFO] [stderr]  --> src/equation_solver.rs:2:5
[INFO] [stderr]   |
[INFO] [stderr] 2 | use std::borrow::Borrow;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `if` condition
[INFO] [stderr]   --> src/equation_solver.rs:77:32
[INFO] [stderr]    |
[INFO] [stderr] 77 |         let new_left_side = if (!flip) {
[INFO] [stderr]    |                                ^^^^^^^ help: remove these parentheses
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_parens)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around `if` condition
[INFO] [stderr]    --> src/equation_solver.rs:101:19
[INFO] [stderr]     |
[INFO] [stderr] 101 |         return if (!flip) {
[INFO] [stderr]     |                   ^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unused import: `crate::equation::*`
[INFO] [stderr]  --> src/main.rs:7:5
[INFO] [stderr]   |
[INFO] [stderr] 7 | use crate::equation::*;
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around assigned value
[INFO] [stderr]   --> src/main.rs:50:26
[INFO] [stderr]    |
[INFO] [stderr] 50 |             let values = (*box_tuple.clone());
[INFO] [stderr]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around assigned value
[INFO] [stderr]   --> src/main.rs:58:26
[INFO] [stderr]    |
[INFO] [stderr] 58 |             let values = (*box_tuple.clone());
[INFO] [stderr]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around assigned value
[INFO] [stderr]   --> src/main.rs:66:26
[INFO] [stderr]    |
[INFO] [stderr] 66 |             let values = (*box_tuple.clone());
[INFO] [stderr]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: unnecessary parentheses around assigned value
[INFO] [stderr]   --> src/main.rs:74:26
[INFO] [stderr]    |
[INFO] [stderr] 74 |             let values = (*box_tuple.clone());
[INFO] [stderr]    |                          ^^^^^^^^^^^^^^^^^^^^ help: remove these parentheses
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/main.rs:37:9
[INFO] [stderr]    |
[INFO] [stderr] 37 |     let mut new_eq_result = solver.solve_step();
[INFO] [stderr]    |         ----^^^^^^^^^^^^^
[INFO] [stderr]    |         |
[INFO] [stderr]    |         help: remove this `mut`
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(unused_mut)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:102:13
[INFO] [stderr]     |
[INFO] [stderr] 102 |         let mut equation = equation::Equation::from_tokens(tokens);
[INFO] [stderr]     |             ----^^^^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/main.rs:108:13
[INFO] [stderr]     |
[INFO] [stderr] 108 |         let mut solver =
[INFO] [stderr]     |             ----^^^^^^
[INFO] [stderr]     |             |
[INFO] [stderr]     |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]   --> src/equation_solver.rs:19:13
[INFO] [stderr]    |
[INFO] [stderr] 19 |         let mut variable_path = self.get_variable_path()?;
[INFO] [stderr]    |             ----^^^^^^^^^^^^^
[INFO] [stderr]    |             |
[INFO] [stderr]    |             help: remove this `mut`
[INFO] [stderr] 
[INFO] [stderr] warning: 12 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.05s
[INFO] [stderr]      Running /opt/rustwide/target/debug/deps/algebra-9c98a04bb09c9252
[INFO] [stdout] 
[INFO] [stdout] running 0 tests
[INFO] [stdout] 
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "4f11b35f76d7e06ff3bc169baadec173c03feae823a50839a2230826970daf01", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "4f11b35f76d7e06ff3bc169baadec173c03feae823a50839a2230826970daf01", kill_on_drop: false }`
[INFO] [stdout] 4f11b35f76d7e06ff3bc169baadec173c03feae823a50839a2230826970daf01