[INFO] fetching crate png_pong 0.8.2...
[INFO] testing png_pong-0.8.2 against 1.75.0 for beta-1.76-1
[INFO] extracting crate png_pong 0.8.2 into /workspace/builds/worker-0-tc1/source
[INFO] validating manifest of crates.io crate png_pong 0.8.2 on toolchain 1.75.0
[INFO] running `Command { std: CARGO_HOME="/workspace/cargo-home" RUSTUP_HOME="/workspace/rustup-home" "/workspace/cargo-home/bin/cargo" "+1.75.0" "metadata" "--manifest-path" "Cargo.toml" "--no-deps", kill_on_drop: false }`
[INFO] started tweaking crates.io crate png_pong 0.8.2
[INFO] finished tweaking crates.io crate png_pong 0.8.2
[INFO] tweaked toml for crates.io crate png_pong 0.8.2 written to /workspace/builds/worker-0-tc1/source/Cargo.toml
[INFO] crate crates.io crate png_pong 0.8.2 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" "+1.75.0" "fetch" "--manifest-path" "Cargo.toml", kill_on_drop: false }`
[INFO] [stderr]     Updating crates.io index
[INFO] [stderr]  Downloading crates ...
[INFO] [stderr]   Downloaded crossbeam-epoch v0.9.4
[INFO] [stderr]   Downloaded pix v0.13.1
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "metadata" "--no-deps" "--format-version=1", kill_on_drop: false }`
[INFO] [stdout] d05f1516172e0bd72cfc0eec84d0135d3a78584ed0494147cd58ad0ea6aa0402
[INFO] running `Command { std: "docker" "start" "-a" "d05f1516172e0bd72cfc0eec84d0135d3a78584ed0494147cd58ad0ea6aa0402", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "inspect" "d05f1516172e0bd72cfc0eec84d0135d3a78584ed0494147cd58ad0ea6aa0402", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "d05f1516172e0bd72cfc0eec84d0135d3a78584ed0494147cd58ad0ea6aa0402", kill_on_drop: false }`
[INFO] [stdout] d05f1516172e0bd72cfc0eec84d0135d3a78584ed0494147cd58ad0ea6aa0402
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "build" "--frozen" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] f731fb9378e14230c5c88da67950bd993a2c82bacf5c886f78a18024646d2bc2
[INFO] running `Command { std: "docker" "start" "-a" "f731fb9378e14230c5c88da67950bd993a2c82bacf5c886f78a18024646d2bc2", kill_on_drop: false }`
[INFO] [stderr]    Compiling miniz_oxide v0.4.4
[INFO] [stderr]    Compiling pix v0.13.1
[INFO] [stderr]    Compiling adler v1.0.2
[INFO] [stderr]    Compiling png_pong v0.8.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: fields `text`, `langtag`, and `transkey` are never read
[INFO] [stdout]   --> src/decode/steps.rs:28:5
[INFO] [stdout]    |
[INFO] [stdout] 27 | struct TextEntry {
[INFO] [stdout]    |        --------- fields in this struct
[INFO] [stdout] 28 |     text: String,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 29 |     langtag: Option<String>,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 30 |     transkey: Option<String>,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `TextEntry` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `has_decoded`, `is_animation`, and `idat_anim` are never read
[INFO] [stdout]   --> src/decode/steps.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 35 | pub struct Steps<R: Read> {
[INFO] [stdout]    |            ----- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 38 |     has_decoded: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 42 |     is_animation: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout] 43 |     // Is IDAT part of the animation?
[INFO] [stdout] 44 |     idat_anim: bool,
[INFO] [stdout]    |     ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Steps` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `coldepth` and `header` are never read
[INFO] [stdout]    --> src/encode/step_enc.rs:119:5
[INFO] [stdout]     |
[INFO] [stdout] 117 | pub struct StepEnc<W: Write> {
[INFO] [stdout]     |            ------- fields in this struct
[INFO] [stdout] 118 |     encoder: ChunkEnc<W>,
[INFO] [stdout] 119 |     coldepth: Option<(ColorType, u32)>,
[INFO] [stdout]     |     ^^^^^^^^
[INFO] [stdout] 120 |     header: Option<ImageHeader>,
[INFO] [stdout]     |     ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `StepEnc` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished dev [optimized + debuginfo] target(s) in 1.33s
[INFO] running `Command { std: "docker" "inspect" "f731fb9378e14230c5c88da67950bd993a2c82bacf5c886f78a18024646d2bc2", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "f731fb9378e14230c5c88da67950bd993a2c82bacf5c886f78a18024646d2bc2", kill_on_drop: false }`
[INFO] [stdout] f731fb9378e14230c5c88da67950bd993a2c82bacf5c886f78a18024646d2bc2
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "test" "--frozen" "--no-run" "--message-format=json", kill_on_drop: false }`
[INFO] [stdout] aaadc01020260d090bd4c49c2bac86dc723b951651694c010783d577e02a5dcb
[INFO] running `Command { std: "docker" "start" "-a" "aaadc01020260d090bd4c49c2bac86dc723b951651694c010783d577e02a5dcb", kill_on_drop: false }`
[INFO] [stderr]    Compiling ucd-trie v0.1.3
[INFO] [stderr]    Compiling lazy_static v1.4.0
[INFO] [stderr]    Compiling crossbeam-utils v0.8.4
[INFO] [stderr]    Compiling serde v1.0.126
[INFO] [stderr]    Compiling memoffset v0.6.3
[INFO] [stderr]    Compiling cfg-if v1.0.0
[INFO] [stderr]    Compiling libc v0.2.94
[INFO] [stderr]    Compiling proc-macro2 v1.0.26
[INFO] [stderr]    Compiling ryu v1.0.5
[INFO] [stderr]    Compiling memchr v2.4.0
[INFO] [stderr]    Compiling rayon-core v1.9.0
[INFO] [stderr]    Compiling either v1.6.1
[INFO] [stderr]    Compiling scopeguard v1.1.0
[INFO] [stderr]    Compiling num-traits v0.2.14
[INFO] [stderr]    Compiling bitflags v1.2.1
[INFO] [stderr]    Compiling byteorder v1.4.3
[INFO] [stderr]    Compiling itoa v0.4.7
[INFO] [stderr]    Compiling serde_json v1.0.64
[INFO] [stderr]    Compiling pest v2.1.3
[INFO] [stderr]    Compiling syn v1.0.72
[INFO] [stderr]    Compiling regex-automata v0.1.9
[INFO] [stderr]    Compiling rayon v1.5.0
[INFO] [stderr]    Compiling unicode-width v0.1.8
[INFO] [stderr]    Compiling serde_derive v1.0.126
[INFO] [stderr]    Compiling plotters-backend v0.3.0
[INFO] [stderr]    Compiling textwrap v0.11.0
[INFO] [stderr]    Compiling itertools v0.9.0
[INFO] [stderr]    Compiling half v1.7.1
[INFO] [stderr]    Compiling same-file v1.0.6
[INFO] [stderr]    Compiling plotters-svg v0.3.0
[INFO] [stderr]    Compiling regex-syntax v0.6.25
[INFO] [stderr]    Compiling walkdir v2.3.2
[INFO] [stderr]    Compiling clap v2.33.3
[INFO] [stderr]    Compiling itertools v0.10.0
[INFO] [stderr]    Compiling csv-core v0.1.10
[INFO] [stderr]    Compiling semver-parser v0.10.2
[INFO] [stderr]    Compiling crossbeam-epoch v0.9.4
[INFO] [stderr]    Compiling crossbeam-channel v0.5.1
[INFO] [stderr]    Compiling num_cpus v1.13.0
[INFO] [stderr]    Compiling quote v1.0.9
[INFO] [stderr]    Compiling crossbeam-deque v0.8.0
[INFO] [stderr]    Compiling semver v0.11.0
[INFO] [stderr]    Compiling plotters v0.3.0
[INFO] [stderr]    Compiling atty v0.2.14
[INFO] [stderr]    Compiling rustc_version v0.3.3
[INFO] [stderr]    Compiling oorandom v11.1.3
[INFO] [stdout] warning: fields `text`, `langtag`, and `transkey` are never read
[INFO] [stdout]   --> src/decode/steps.rs:28:5
[INFO] [stdout]    |
[INFO] [stdout] 27 | struct TextEntry {
[INFO] [stdout]    |        --------- fields in this struct
[INFO] [stdout] 28 |     text: String,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 29 |     langtag: Option<String>,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 30 |     transkey: Option<String>,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `TextEntry` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `has_decoded`, `is_animation`, and `idat_anim` are never read
[INFO] [stdout]   --> src/decode/steps.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 35 | pub struct Steps<R: Read> {
[INFO] [stdout]    |            ----- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 38 |     has_decoded: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 42 |     is_animation: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout] 43 |     // Is IDAT part of the animation?
[INFO] [stdout] 44 |     idat_anim: bool,
[INFO] [stdout]    |     ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Steps` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `coldepth` and `header` are never read
[INFO] [stdout]    --> src/encode/step_enc.rs:119:5
[INFO] [stdout]     |
[INFO] [stdout] 117 | pub struct StepEnc<W: Write> {
[INFO] [stdout]     |            ------- fields in this struct
[INFO] [stdout] 118 |     encoder: ChunkEnc<W>,
[INFO] [stdout] 119 |     coldepth: Option<(ColorType, u32)>,
[INFO] [stdout]     |     ^^^^^^^^
[INFO] [stdout] 120 |     header: Option<ImageHeader>,
[INFO] [stdout]     |     ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `StepEnc` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]    Compiling regex v1.5.4
[INFO] [stderr]    Compiling cast v0.2.6
[INFO] [stderr]    Compiling criterion-plot v0.4.3
[INFO] [stderr]    Compiling bstr v0.2.16
[INFO] [stderr]    Compiling serde_cbor v0.11.1
[INFO] [stderr]    Compiling csv v1.1.6
[INFO] [stderr]    Compiling tinytemplate v1.2.1
[INFO] [stderr]    Compiling criterion v0.3.4
[INFO] [stderr]    Compiling png_pong v0.8.2 (/opt/rustwide/workdir)
[INFO] [stdout] warning: fields `text`, `langtag`, and `transkey` are never read
[INFO] [stdout]   --> src/decode/steps.rs:28:5
[INFO] [stdout]    |
[INFO] [stdout] 27 | struct TextEntry {
[INFO] [stdout]    |        --------- fields in this struct
[INFO] [stdout] 28 |     text: String,
[INFO] [stdout]    |     ^^^^
[INFO] [stdout] 29 |     langtag: Option<String>,
[INFO] [stdout]    |     ^^^^^^^
[INFO] [stdout] 30 |     transkey: Option<String>,
[INFO] [stdout]    |     ^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `TextEntry` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout]    = note: `#[warn(dead_code)]` on by default
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `has_decoded`, `is_animation`, and `idat_anim` are never read
[INFO] [stdout]   --> src/decode/steps.rs:38:5
[INFO] [stdout]    |
[INFO] [stdout] 35 | pub struct Steps<R: Read> {
[INFO] [stdout]    |            ----- fields in this struct
[INFO] [stdout] ...
[INFO] [stdout] 38 |     has_decoded: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^
[INFO] [stdout] ...
[INFO] [stdout] 42 |     is_animation: bool,
[INFO] [stdout]    |     ^^^^^^^^^^^^
[INFO] [stdout] 43 |     // Is IDAT part of the animation?
[INFO] [stdout] 44 |     idat_anim: bool,
[INFO] [stdout]    |     ^^^^^^^^^
[INFO] [stdout]    |
[INFO] [stdout]    = note: `Steps` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: fields `coldepth` and `header` are never read
[INFO] [stdout]    --> src/encode/step_enc.rs:119:5
[INFO] [stdout]     |
[INFO] [stdout] 117 | pub struct StepEnc<W: Write> {
[INFO] [stdout]     |            ------- fields in this struct
[INFO] [stdout] 118 |     encoder: ChunkEnc<W>,
[INFO] [stdout] 119 |     coldepth: Option<(ColorType, u32)>,
[INFO] [stdout]     |     ^^^^^^^^
[INFO] [stdout] 120 |     header: Option<ImageHeader>,
[INFO] [stdout]     |     ^^^^^^
[INFO] [stdout]     |
[INFO] [stdout]     = note: `StepEnc` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] warning: 3 warnings emitted
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stderr]     Finished test [optimized + debuginfo] target(s) in 15.94s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: criterion v0.3.4
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 1`
[INFO] running `Command { std: "docker" "inspect" "aaadc01020260d090bd4c49c2bac86dc723b951651694c010783d577e02a5dcb", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "aaadc01020260d090bd4c49c2bac86dc723b951651694c010783d577e02a5dcb", kill_on_drop: false }`
[INFO] [stdout] aaadc01020260d090bd4c49c2bac86dc723b951651694c010783d577e02a5dcb
[INFO] running `Command { std: "docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-0-tc1/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" "RUSTDOCFLAGS=--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@sha256:2788e3201cd34a07e3172128adcd8b3090168a8e3bcc40d7c032b9dda1df7d1c" "/opt/rustwide/cargo-home/bin/cargo" "+1.75.0" "test" "--frozen", kill_on_drop: false }`
[INFO] [stdout] 21176a99f010a7199202f81ff82faf850487d062b3b193f0472aa2d47dc4a6e8
[INFO] running `Command { std: "docker" "start" "-a" "21176a99f010a7199202f81ff82faf850487d062b3b193f0472aa2d47dc4a6e8", kill_on_drop: false }`
[INFO] [stderr] warning: fields `text`, `langtag`, and `transkey` are never read
[INFO] [stderr]   --> src/decode/steps.rs:28:5
[INFO] [stderr]    |
[INFO] [stderr] 27 | struct TextEntry {
[INFO] [stderr]    |        --------- fields in this struct
[INFO] [stderr] 28 |     text: String,
[INFO] [stderr]    |     ^^^^
[INFO] [stderr] 29 |     langtag: Option<String>,
[INFO] [stderr]    |     ^^^^^^^
[INFO] [stderr] 30 |     transkey: Option<String>,
[INFO] [stderr]    |     ^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `TextEntry` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stderr]    = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: fields `has_decoded`, `is_animation`, and `idat_anim` are never read
[INFO] [stderr]   --> src/decode/steps.rs:38:5
[INFO] [stderr]    |
[INFO] [stderr] 35 | pub struct Steps<R: Read> {
[INFO] [stderr]    |            ----- fields in this struct
[INFO] [stderr] ...
[INFO] [stderr] 38 |     has_decoded: bool,
[INFO] [stderr]    |     ^^^^^^^^^^^
[INFO] [stderr] ...
[INFO] [stderr] 42 |     is_animation: bool,
[INFO] [stderr]    |     ^^^^^^^^^^^^
[INFO] [stderr] 43 |     // Is IDAT part of the animation?
[INFO] [stderr] 44 |     idat_anim: bool,
[INFO] [stderr]    |     ^^^^^^^^^
[INFO] [stderr]    |
[INFO] [stderr]    = note: `Steps` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stderr] 
[INFO] [stderr] warning: fields `coldepth` and `header` are never read
[INFO] [stderr]    --> src/encode/step_enc.rs:119:5
[INFO] [stderr]     |
[INFO] [stderr] 117 | pub struct StepEnc<W: Write> {
[INFO] [stderr]     |            ------- fields in this struct
[INFO] [stderr] 118 |     encoder: ChunkEnc<W>,
[INFO] [stderr] 119 |     coldepth: Option<(ColorType, u32)>,
[INFO] [stderr]     |     ^^^^^^^^
[INFO] [stderr] 120 |     header: Option<ImageHeader>,
[INFO] [stderr]     |     ^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `StepEnc` has a derived impl for the trait `Debug`, but this is intentionally ignored during dead code analysis
[INFO] [stderr] 
[INFO] [stderr] warning: `png_pong` (lib) generated 3 warnings
[INFO] [stderr] warning: `png_pong` (lib test) generated 3 warnings (3 duplicates)
[INFO] [stderr]     Finished test [optimized + debuginfo] target(s) in 0.05s
[INFO] [stderr] warning: the following packages contain code that will be rejected by a future version of Rust: criterion v0.3.4
[INFO] [stderr] note: to see what the problems were, use the option `--future-incompat-report`, or run `cargo report future-incompatibilities --id 1`
[INFO] [stderr]      Running unittests src/lib.rs (/opt/rustwide/target/debug/deps/png_pong-9c4f4fdd54e7a5cf)
[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] [stderr]    Doc-tests png_pong
[INFO] [stdout] 
[INFO] [stdout] running 1 test
[INFO] [stdout] test src/lib.rs - (line 21) ... FAILED
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout] 
[INFO] [stdout] ---- src/lib.rs - (line 21) stdout ----
[INFO] [stdout] Test executable failed (exit status: 101).
[INFO] [stdout] 
[INFO] [stdout] stderr:
[INFO] [stdout] thread 'main' panicked at src/lib.rs:13:41:
[INFO] [stdout] Failed to save image: Os { code: 30, kind: ReadOnlyFilesystem, message: "Read-only file system" }
[INFO] [stdout] stack backtrace:
[INFO] [stdout]    0:     0x55b67576c3ac - std::backtrace_rs::backtrace::libunwind::trace::ha637c64ce894333a
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/../../backtrace/src/backtrace/libunwind.rs:104:5
[INFO] [stdout]    1:     0x55b67576c3ac - std::backtrace_rs::backtrace::trace_unsynchronized::h47f62dea28e0c88d
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/../../backtrace/src/backtrace/mod.rs:66:5
[INFO] [stdout]    2:     0x55b67576c3ac - std::sys_common::backtrace::_print_fmt::h9eef0abe20ede486
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/sys_common/backtrace.rs:67:5
[INFO] [stdout]    3:     0x55b67576c3ac - <std::sys_common::backtrace::_print::DisplayBacktrace as core::fmt::Display>::fmt::hed7f999df88cc644
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/sys_common/backtrace.rs:44:22
[INFO] [stdout]    4:     0x55b67578c150 - core::fmt::rt::Argument::fmt::h1539a9308b8d058d
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/core/src/fmt/rt.rs:142:9
[INFO] [stdout]    5:     0x55b67578c150 - core::fmt::write::h3a39390d8560d9c9
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/core/src/fmt/mod.rs:1120:17
[INFO] [stdout]    6:     0x55b67576a85f - std::io::Write::write_fmt::h5fc9997dfe05f882
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/io/mod.rs:1762:15
[INFO] [stdout]    7:     0x55b67576c194 - std::sys_common::backtrace::_print::h894006fb5c6f3d45
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/sys_common/backtrace.rs:47:5
[INFO] [stdout]    8:     0x55b67576c194 - std::sys_common::backtrace::print::h23a2d212c6fff936
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/sys_common/backtrace.rs:34:9
[INFO] [stdout]    9:     0x55b67576d6a7 - std::panicking::default_hook::{{closure}}::h8a1d2ee00185001a
[INFO] [stdout]   10:     0x55b67576d40f - std::panicking::default_hook::h6038f2eba384e475
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panicking.rs:292:9
[INFO] [stdout]   11:     0x55b67576db28 - std::panicking::rust_panic_with_hook::h2b5517d590cab22e
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panicking.rs:779:13
[INFO] [stdout]   12:     0x55b67576da0e - std::panicking::begin_panic_handler::{{closure}}::h233112c06e0ef43e
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panicking.rs:657:13
[INFO] [stdout]   13:     0x55b67576c876 - std::sys_common::backtrace::__rust_end_short_backtrace::h6e893f24d7ebbff8
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/sys_common/backtrace.rs:170:18
[INFO] [stdout]   14:     0x55b67576d772 - rust_begin_unwind
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panicking.rs:645:5
[INFO] [stdout]   15:     0x55b675723055 - core::panicking::panic_fmt::hbf0e066aabfa482c
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/core/src/panicking.rs:72:14
[INFO] [stdout]   16:     0x55b6757234b3 - core::result::unwrap_failed::hddb4fea594200c52
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/core/src/result.rs:1653:5
[INFO] [stdout]   17:     0x55b675728b93 - core::result::Result<T,E>::expect::h8aa24a497a63022f
[INFO] [stdout]   18:     0x55b67573f6e6 - rust_out::main::_doctest_main_src_lib_rs_21_0::h2af255efdd62dacc
[INFO] [stdout]   19:     0x55b67573f476 - rust_out::main::hc20c0d07e2402830
[INFO] [stdout]   20:     0x55b675726723 - core::ops::function::FnOnce::call_once::hbc459743598298c4
[INFO] [stdout]   21:     0x55b675724466 - std::sys_common::backtrace::__rust_begin_short_backtrace::h62debe7d3058b76a
[INFO] [stdout]   22:     0x55b675725409 - std::rt::lang_start::{{closure}}::h8f486f3e1e6418b2
[INFO] [stdout]   23:     0x55b675767d87 - core::ops::function::impls::<impl core::ops::function::FnOnce<A> for &F>::call_once::hd95060ecd5e1ca24
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/core/src/ops/function.rs:284:13
[INFO] [stdout]   24:     0x55b675767d87 - std::panicking::try::do_call::h6e8cf51db32a6e4b
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panicking.rs:552:40
[INFO] [stdout]   25:     0x55b675767d87 - std::panicking::try::h3a52eefe24fe3c29
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panicking.rs:516:19
[INFO] [stdout]   26:     0x55b675767d87 - std::panic::catch_unwind::h24c28c23c02c3841
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panic.rs:142:14
[INFO] [stdout]   27:     0x55b675767d87 - std::rt::lang_start_internal::{{closure}}::h705d3c9cbc06ef47
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/rt.rs:148:48
[INFO] [stdout]   28:     0x55b675767d87 - std::panicking::try::do_call::ha21f52ba13158470
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panicking.rs:552:40
[INFO] [stdout]   29:     0x55b675767d87 - std::panicking::try::h5581346bf6aeb1f8
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panicking.rs:516:19
[INFO] [stdout]   30:     0x55b675767d87 - std::panic::catch_unwind::h7919645a6b72e25b
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/panic.rs:142:14
[INFO] [stdout]   31:     0x55b675767d87 - std::rt::lang_start_internal::h12de51168669836e
[INFO] [stdout]                                at /rustc/82e1608dfa6e0b5569232559e3d385fea5a93112/library/std/src/rt.rs:148:20
[INFO] [stdout]   32:     0x55b6757253e7 - std::rt::lang_start::h2c48f91a7bf85629
[INFO] [stdout]   33:     0x55b67573f915 - main
[INFO] [stdout]   34:     0x7f67c57c7d90 - <unknown>
[INFO] [stdout]   35:     0x7f67c57c7e40 - __libc_start_main
[INFO] [stdout]   36:     0x55b675723775 - _start
[INFO] [stdout]   37:                0x0 - <unknown>
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] 
[INFO] [stdout] failures:
[INFO] [stdout]     src/lib.rs - (line 21)
[INFO] [stdout] 
[INFO] [stdout] test result: FAILED. 0 passed; 1 failed; 0 ignored; 0 measured; 0 filtered out; finished in 0.35s
[INFO] [stdout] 
[INFO] [stderr] error: doctest failed, to rerun pass `--doc`
[INFO] running `Command { std: "docker" "inspect" "21176a99f010a7199202f81ff82faf850487d062b3b193f0472aa2d47dc4a6e8", kill_on_drop: false }`
[INFO] running `Command { std: "docker" "rm" "-f" "21176a99f010a7199202f81ff82faf850487d062b3b193f0472aa2d47dc4a6e8", kill_on_drop: false }`
[INFO] [stdout] 21176a99f010a7199202f81ff82faf850487d062b3b193f0472aa2d47dc4a6e8
