[INFO] cloning repository https://github.com/ijks/esolangs-rs
[INFO] running `Command { std: "git" "-c" "credential.helper=" "-c" "credential.helper=/workspace/cargo-home/bin/git-credential-null" "clone" "--bare" "https://github.com/ijks/esolangs-rs" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fijks%2Fesolangs-rs", kill_on_drop: false }`
[INFO] [stderr] Cloning into bare repository '/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fijks%2Fesolangs-rs'...
[INFO] running `Command { std: "git" "rev-parse" "HEAD", kill_on_drop: false }`
[INFO] [stdout] 9aba1332285c0c330988fe7d60d35987fdf2af74
[INFO] checking ijks/esolangs-rs against try#4f260f0f20b3133d20cfb50353c0221943af5796+rustflags=-Dunmustuse_in_always_ok for pr-148577
[INFO] running `Command { std: "git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Fijks%2Fesolangs-rs" "/workspace/builds/worker-7-tc2/source", kill_on_drop: false }`
[INFO] [stderr] Cloning into '/workspace/builds/worker-7-tc2/source'...
[INFO] [stderr] done.
[INFO] removed /workspace/builds/worker-7-tc2/source/rust-toolchain
[INFO] started tweaking git repo https://github.com/ijks/esolangs-rs
[INFO] finished tweaking git repo https://github.com/ijks/esolangs-rs
[INFO] tweaked toml for git repo https://github.com/ijks/esolangs-rs written to /workspace/builds/worker-7-tc2/source/Cargo.toml
[INFO] validating manifest of git repo https://github.com/ijks/esolangs-rs on toolchain 4f260f0f20b3133d20cfb50353c0221943af5796
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] crate git repo https://github.com/ijks/esolangs-rs already has a lockfile, it will not be regenerated
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 84474a3e9704f2fe9939c29c416d0ca90970305a0851e17a96aa20fb519e8ba1
[INFO] running `Command { std: "docker" "start" "-a" "84474a3e9704f2fe9939c29c416d0ca90970305a0851e17a96aa20fb519e8ba1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "84474a3e9704f2fe9939c29c416d0ca90970305a0851e17a96aa20fb519e8ba1", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "84474a3e9704f2fe9939c29c416d0ca90970305a0851e17a96aa20fb519e8ba1", kill_on_drop: false }`
[INFO] [stdout] 84474a3e9704f2fe9939c29c416d0ca90970305a0851e17a96aa20fb519e8ba1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-7-tc2/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 -Dunmustuse_in_always_ok" "-e" "RUSTDOCFLAGS=--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@sha256:4848fb76d95f26979359cc7e45710b1dbc8f3acb7aeedee7c460d7702230f228" "/opt/rustwide/cargo-home/bin/cargo" "+4f260f0f20b3133d20cfb50353c0221943af5796" "check" "--frozen" "--all" "--all-targets" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] 846ade12d8ba6b345bdf205f962e9c707527e44e926912610da9de5474648639
[INFO] running `Command { std: "docker" "start" "-a" "846ade12d8ba6b345bdf205f962e9c707527e44e926912610da9de5474648639", kill_on_drop: false }`
[INFO] [stderr]    Compiling libc v0.2.80
[INFO] [stderr]    Compiling getrandom v0.1.15
[INFO] [stderr]    Compiling syn v1.0.53
[INFO] [stderr]    Compiling byteorder v1.3.4
[INFO] [stderr]     Checking bit-vec v0.6.2
[INFO] [stderr]     Checking regex-syntax v0.6.21
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]     Checking utf8-chars v1.0.0
[INFO] [stderr]     Checking emmental v0.1.0 (/opt/rustwide/workdir/emmental)
[INFO] [stderr]    Compiling quote v1.0.7
[INFO] [stdout] warning: struct `StandardIO` is never constructed
[INFO] [stdout]   --> emmental/src/io.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 15 | pub struct StandardIO;
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<u8, !>
[INFO] [stdout]   --> emmental/src/io.rs:54:62
[INFO] [stdout]    |
[INFO] [stdout] 54 |       fn read_symbol(&mut self) -> Result<Symbol, Self::Error> {
[INFO] [stdout]    |  ______________________________________________________________^
[INFO] [stdout] 55 | |         const EOT: Symbol = 4;
[INFO] [stdout] 56 | |
[INFO] [stdout] 57 | |         Ok(match self.input {
[INFO] [stdout] ...  |
[INFO] [stdout] 63 | |         })
[INFO] [stdout] 64 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<u8, !>
[INFO] [stdout]   --> emmental/src/io.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 | /         Ok(match self.input {
[INFO] [stdout] 58 | |             [] => EOT,
[INFO] [stdout] 59 | |             [s, rest @ ..] => {
[INFO] [stdout] 60 | |                 self.input = rest;
[INFO] [stdout] ...  |
[INFO] [stdout] 63 | |         })
[INFO] [stdout]    | |__________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: for loop over an `Option`. This is more readably written as an `if let` statement
[INFO] [stdout]   --> emmental/src/state.rs:28:21
[INFO] [stdout]    |
[INFO] [stdout] 28 |         for &sym in program.next() {
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(for_loops_over_fallibles)]` on by default
[INFO] [stdout] help: to iterate over `program` remove the call to `next`
[INFO] [stdout]    |
[INFO] [stdout] 28 -         for &sym in program.next() {
[INFO] [stdout] 28 +         for &sym in program.by_ref() {
[INFO] [stdout]    |
[INFO] [stdout] help: consider using `if let` to clear intent
[INFO] [stdout]    |
[INFO] [stdout] 28 -         for &sym in program.next() {
[INFO] [stdout] 28 +         if let Some(&sym) = program.next() {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `emmental` (lib test) due to 2 previous errors; 2 warnings emitted
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stdout] warning: struct `StandardIO` is never constructed
[INFO] [stdout]   --> emmental/src/io.rs:15:12
[INFO] [stdout]    |
[INFO] [stdout] 15 | pub struct StandardIO;
[INFO] [stdout]    |            ^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(dead_code)]` (part of `#[warn(unused)]`) on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<u8, !>
[INFO] [stdout]   --> emmental/src/io.rs:54:62
[INFO] [stdout]    |
[INFO] [stdout] 54 |       fn read_symbol(&mut self) -> Result<Symbol, Self::Error> {
[INFO] [stdout]    |  ______________________________________________________________^
[INFO] [stdout] 55 | |         const EOT: Symbol = 4;
[INFO] [stdout] 56 | |
[INFO] [stdout] 57 | |         Ok(match self.input {
[INFO] [stdout] ...  |
[INFO] [stdout] 63 | |         })
[INFO] [stdout] 64 | |     }
[INFO] [stdout]    | |_____^
[INFO] [stdout]    |
[INFO] [stdout]    = note: requested on the command line with `-D unmustuse-in-always-ok`
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] error: this type will no longer be must used: Result<u8, !>
[INFO] [stdout]   --> emmental/src/io.rs:57:9
[INFO] [stdout]    |
[INFO] [stdout] 57 | /         Ok(match self.input {
[INFO] [stdout] 58 | |             [] => EOT,
[INFO] [stdout] 59 | |             [s, rest @ ..] => {
[INFO] [stdout] 60 | |                 self.input = rest;
[INFO] [stdout] ...  |
[INFO] [stdout] 63 | |         })
[INFO] [stdout]    | |__________^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: for loop over an `Option`. This is more readably written as an `if let` statement
[INFO] [stdout]   --> emmental/src/state.rs:28:21
[INFO] [stdout]    |
[INFO] [stdout] 28 |         for &sym in program.next() {
[INFO] [stdout]    |                     ^^^^^^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(for_loops_over_fallibles)]` on by default
[INFO] [stdout] help: to iterate over `program` remove the call to `next`
[INFO] [stdout]    |
[INFO] [stdout] 28 -         for &sym in program.next() {
[INFO] [stdout] 28 +         for &sym in program.by_ref() {
[INFO] [stdout]    |
[INFO] [stdout] help: consider using `if let` to clear intent
[INFO] [stdout]    |
[INFO] [stdout] 28 -         for &sym in program.next() {
[INFO] [stdout] 28 +         if let Some(&sym) = program.next() {
[INFO] [stdout]    |
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr] error: could not compile `emmental` (lib) due to 2 previous errors; 2 warnings emitted
[INFO] running `Command { std: "docker" "inspect" "846ade12d8ba6b345bdf205f962e9c707527e44e926912610da9de5474648639", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "846ade12d8ba6b345bdf205f962e9c707527e44e926912610da9de5474648639", kill_on_drop: false }`
[INFO] [stdout] 846ade12d8ba6b345bdf205f962e9c707527e44e926912610da9de5474648639
