[INFO] fetching crate ogg_vorbis_ref 0.0.3...
[INFO] testing ogg_vorbis_ref-0.0.3 against 1.54.0 for beta-1.55-1
[INFO] extracting crate ogg_vorbis_ref 0.0.3 into /workspace/builds/worker-13/source
[INFO] validating manifest of crates.io crate ogg_vorbis_ref 0.0.3 on toolchain 1.54.0
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate ogg_vorbis_ref 0.0.3
[INFO] finished tweaking crates.io crate ogg_vorbis_ref 0.0.3
[INFO] tweaked toml for crates.io crate ogg_vorbis_ref 0.0.3 written to /workspace/builds/worker-13/source/Cargo.toml
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "generate-lockfile" "--manifest-path" "Cargo.toml" "-Zno-index-update", kill_on_drop: false }`
[INFO] [stderr]     Blocking waiting for file lock on package cache
[INFO] running `Command { std: "/workspace/cargo-home/bin/cargo" "+1.54.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] 6da1bb4559daf5007f44ca0f8adfc27318bf2ba61d5df9c3b3cc71d293cdef26
[INFO] running `Command { std: "docker" "start" "-a" "6da1bb4559daf5007f44ca0f8adfc27318bf2ba61d5df9c3b3cc71d293cdef26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "6da1bb4559daf5007f44ca0f8adfc27318bf2ba61d5df9c3b3cc71d293cdef26", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "6da1bb4559daf5007f44ca0f8adfc27318bf2ba61d5df9c3b3cc71d293cdef26", kill_on_drop: false }`
[INFO] [stdout] 6da1bb4559daf5007f44ca0f8adfc27318bf2ba61d5df9c3b3cc71d293cdef26
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] d9914b37fdf5626c02ea2b7cfb86c6b7a536c56534f9b79fc1af6482e34aba7d
[INFO] running `Command { std: "docker" "start" "-a" "d9914b37fdf5626c02ea2b7cfb86c6b7a536c56534f9b79fc1af6482e34aba7d", kill_on_drop: false }`
[INFO] [stderr]    Compiling gcc v0.3.55
[INFO] [stderr]    Compiling ogg-sys v0.0.9
[INFO] [stderr]    Compiling vorbis-sys v0.0.8
[INFO] [stderr]    Compiling ogg_vorbis_ref v0.0.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |         try!(Self::page_out(&mut self.reader, &mut self.sync, &mut page, self.buf_len));
[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/lib.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |         try!(Self::page_in(&mut *state, &mut *page));
[INFO] [stdout]    |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:55:13
[INFO] [stdout]    |
[INFO] [stdout] 55 |             try!(self.reset());
[INFO] [stdout]    |             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:67:17
[INFO] [stdout]    |
[INFO] [stdout] 67 |                 try!(Self::page_out(&mut self.reader, &mut *self.sync, &mut *stream.page, self.buf_len));
[INFO] [stdout]    |                 ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:68:17
[INFO] [stdout]    |
[INFO] [stdout] 68 |                 try!(Self::page_in(&mut *stream.state, &mut *stream.page));
[INFO] [stdout]    |                 ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:104:24
[INFO] [stdout]     |
[INFO] [stdout] 104 |             let read = try!(reader.read(buf));
[INFO] [stdout]     |                        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:177:13
[INFO] [stdout]     |
[INFO] [stdout] 177 |         let mut synth = self.synth.as_mut().unwrap();
[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: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [unoptimized + debuginfo] target(s) in 4.15s
[INFO] running `Command { std: "docker" "inspect" "d9914b37fdf5626c02ea2b7cfb86c6b7a536c56534f9b79fc1af6482e34aba7d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d9914b37fdf5626c02ea2b7cfb86c6b7a536c56534f9b79fc1af6482e34aba7d", kill_on_drop: false }`
[INFO] [stdout] d9914b37fdf5626c02ea2b7cfb86c6b7a536c56534f9b79fc1af6482e34aba7d
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] c6b4e75b4e5620744cbdacef775146facde4330fbd92c9e03a61a27e05e9931b
[INFO] running `Command { std: "docker" "start" "-a" "c6b4e75b4e5620744cbdacef775146facde4330fbd92c9e03a61a27e05e9931b", kill_on_drop: false }`
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |         try!(Self::page_out(&mut self.reader, &mut self.sync, &mut page, self.buf_len));
[INFO] [stdout]    |         ^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `#[warn(deprecated)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling ogg_vorbis_ref v0.0.3 (/opt/rustwide/workdir)
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |         try!(Self::page_in(&mut *state, &mut *page));
[INFO] [stdout]    |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:55:13
[INFO] [stdout]    |
[INFO] [stdout] 55 |             try!(self.reset());
[INFO] [stdout]    |             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:67:17
[INFO] [stdout]    |
[INFO] [stdout] 67 |                 try!(Self::page_out(&mut self.reader, &mut *self.sync, &mut *stream.page, self.buf_len));
[INFO] [stdout]    |                 ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:68:17
[INFO] [stdout]    |
[INFO] [stdout] 68 |                 try!(Self::page_in(&mut *stream.state, &mut *stream.page));
[INFO] [stdout]    |                 ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:104:24
[INFO] [stdout]     |
[INFO] [stdout] 104 |             let read = try!(reader.read(buf));
[INFO] [stdout]     |                        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:177:13
[INFO] [stdout]     |
[INFO] [stdout] 177 |         let mut synth = self.synth.as_mut().unwrap();
[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: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:39:9
[INFO] [stdout]    |
[INFO] [stdout] 39 |         try!(Self::page_out(&mut self.reader, &mut self.sync, &mut page, self.buf_len));
[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/lib.rs:43:9
[INFO] [stdout]    |
[INFO] [stdout] 43 |         try!(Self::page_in(&mut *state, &mut *page));
[INFO] [stdout]    |         ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:55:13
[INFO] [stdout]    |
[INFO] [stdout] 55 |             try!(self.reset());
[INFO] [stdout]    |             ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:67:17
[INFO] [stdout]    |
[INFO] [stdout] 67 |                 try!(Self::page_out(&mut self.reader, &mut *self.sync, &mut *stream.page, self.buf_len));
[INFO] [stdout]    |                 ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]   --> src/lib.rs:68:17
[INFO] [stdout]    |
[INFO] [stdout] 68 |                 try!(Self::page_in(&mut *stream.state, &mut *stream.page));
[INFO] [stdout]    |                 ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout]    --> src/lib.rs:104:24
[INFO] [stdout]     |
[INFO] [stdout] 104 |             let read = try!(reader.read(buf));
[INFO] [stdout]     |                        ^^^
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: variable does not need to be mutable
[INFO] [stdout]    --> src/lib.rs:177:13
[INFO] [stdout]     |
[INFO] [stdout] 177 |         let mut synth = self.synth.as_mut().unwrap();
[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: 7 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.68s
[INFO] running `Command { std: "docker" "inspect" "c6b4e75b4e5620744cbdacef775146facde4330fbd92c9e03a61a27e05e9931b", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "c6b4e75b4e5620744cbdacef775146facde4330fbd92c9e03a61a27e05e9931b", kill_on_drop: false }`
[INFO] [stdout] c6b4e75b4e5620744cbdacef775146facde4330fbd92c9e03a61a27e05e9931b
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-13/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=warn" "-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@sha256:34b6a614d2c27851fe6cbf88fbd1137609cefab8b10d0615aaeb6fd47975d74e" "/opt/rustwide/cargo-home/bin/cargo" "+1.54.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] d35ee4a308ae1d27e3ae17d8d4b6a0113061c5c3e11105afae411daa7f43ed0d
[INFO] running `Command { std: "docker" "start" "-a" "d35ee4a308ae1d27e3ae17d8d4b6a0113061c5c3e11105afae411daa7f43ed0d", kill_on_drop: false }`
[INFO] [stdout] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stdout] running 0 tests
[INFO] [stderr]   --> src/lib.rs:39:9
[INFO] [stdout] 
[INFO] [stderr]    |
[INFO] [stdout] test result: ok. 0 passed; 0 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.00s
[INFO] [stderr] 39 |         try!(Self::page_out(&mut self.reader, &mut self.sync, &mut page, self.buf_len));
[INFO] [stdout] 
[INFO] [stderr]    |         ^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(deprecated)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/lib.rs:43:9
[INFO] [stderr]    |
[INFO] [stderr] 43 |         try!(Self::page_in(&mut *state, &mut *page));
[INFO] [stderr]    |         ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/lib.rs:55:13
[INFO] [stderr]    |
[INFO] [stderr] 55 |             try!(self.reset());
[INFO] [stderr]    |             ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/lib.rs:67:17
[INFO] [stderr]    |
[INFO] [stderr] 67 |                 try!(Self::page_out(&mut self.reader, &mut *self.sync, &mut *stream.page, self.buf_len));
[INFO] [stderr]    |                 ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/lib.rs:68:17
[INFO] [stderr]    |
[INFO] [stderr] 68 |                 try!(Self::page_in(&mut *stream.state, &mut *stream.page));
[INFO] [stderr]    |                 ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]    --> src/lib.rs:104:24
[INFO] [stderr]     |
[INFO] [stderr] 104 |             let read = try!(reader.read(buf));
[INFO] [stderr]     |                        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/lib.rs:177:13
[INFO] [stderr]     |
[INFO] [stderr] 177 |         let mut synth = self.synth.as_mut().unwrap();
[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: 7 warnings emitted
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/lib.rs:39:9
[INFO] [stderr]    |
[INFO] [stderr] 39 |         try!(Self::page_out(&mut self.reader, &mut self.sync, &mut page, self.buf_len));
[INFO] [stderr]    |         ^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `#[warn(deprecated)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/lib.rs:43:9
[INFO] [stderr]    |
[INFO] [stderr] 43 |         try!(Self::page_in(&mut *state, &mut *page));
[INFO] [stderr]    |         ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/lib.rs:55:13
[INFO] [stderr]    |
[INFO] [stderr] 55 |             try!(self.reset());
[INFO] [stderr]    |             ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/lib.rs:67:17
[INFO] [stderr]    |
[INFO] [stderr] 67 |                 try!(Self::page_out(&mut self.reader, &mut *self.sync, &mut *stream.page, self.buf_len));
[INFO] [stderr]    |                 ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]   --> src/lib.rs:68:17
[INFO] [stderr]    |
[INFO] [stderr] 68 |                 try!(Self::page_in(&mut *stream.state, &mut *stream.page));
[INFO] [stderr]    |                 ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: use of deprecated macro `try`: use the `?` operator instead
[INFO] [stderr]    --> src/lib.rs:104:24
[INFO] [stderr]     |
[INFO] [stderr] 104 |             let read = try!(reader.read(buf));
[INFO] [stderr]     |                        ^^^
[INFO] [stderr] 
[INFO] [stderr] warning: variable does not need to be mutable
[INFO] [stderr]    --> src/lib.rs:177:13
[INFO] [stderr]     |
[INFO] [stderr] 177 |         let mut synth = self.synth.as_mut().unwrap();
[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: 7 warnings emitted
[INFO] [stderr] 
[INFO] [stderr]     Finished test [unoptimized + debuginfo] target(s) in 0.01s
[INFO] [stderr]      Running unittests (/opt/rustwide/target/debug/deps/ogg_vorbis_ref-ac78a37d634eaf86)
[INFO] [stderr]    Doc-tests ogg_vorbis_ref
[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; finished in 0.00s
[INFO] [stdout] 
[INFO] running `Command { std: "docker" "inspect" "d35ee4a308ae1d27e3ae17d8d4b6a0113061c5c3e11105afae411daa7f43ed0d", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d35ee4a308ae1d27e3ae17d8d4b6a0113061c5c3e11105afae411daa7f43ed0d", kill_on_drop: false }`
[INFO] [stdout] d35ee4a308ae1d27e3ae17d8d4b6a0113061c5c3e11105afae411daa7f43ed0d
