[INFO] updating cached repository fijk/png-rs
[INFO] running `"git" "fetch" "--all"`
[INFO] [stdout] Fetching origin
[INFO] [stderr] From git://github.com/fijk/png-rs
[INFO] [stderr]  * branch            HEAD       -> FETCH_HEAD
[INFO] running `"git" "clone" "work/cache/sources/gh/fijk/png-rs" "work/ex/beta-1.38-1/sources/1.37.0/gh/fijk/png-rs"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/1.37.0/gh/fijk/png-rs'...
[INFO] [stderr] done.
[INFO] running `"git" "clone" "work/cache/sources/gh/fijk/png-rs" "work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/fijk/png-rs"`
[INFO] [stderr] Cloning into 'work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/fijk/png-rs'...
[INFO] [stderr] done.
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 39d416b427ba5f9b4b8f447b46851ff20f131615
[INFO] sha for GitHub repo fijk/png-rs: 39d416b427ba5f9b4b8f447b46851ff20f131615
[INFO] validating manifest of fijk/png-rs on toolchain 1.37.0
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] validating manifest of fijk/png-rs on toolchain beta-2019-08-13
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started frobbing fijk/png-rs
[INFO] finished frobbing fijk/png-rs
[INFO] frobbed toml for fijk/png-rs written to work/ex/beta-1.38-1/sources/1.37.0/gh/fijk/png-rs/Cargo.toml
[INFO] started frobbing fijk/png-rs
[INFO] finished frobbing fijk/png-rs
[INFO] frobbed toml for fijk/png-rs written to work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/fijk/png-rs/Cargo.toml
[INFO] crate fijk/png-rs already has a lockfile, it will not be regenerated
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+1.37.0" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"/mnt/big/crater/work/local/cargo-home/bin/cargo" "+beta-2019-08-13" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] testing fijk/png-rs against beta-2019-08-13 for beta-1.38-1
[INFO] running `"docker" "create" "-v" "/mnt/big/crater/work/local/target-dirs/beta-1.38-1/worker-1/beta-2019-08-13:/opt/crater/target:rw,Z" "-v" "/mnt/big/crater/work/ex/beta-1.38-1/sources/beta-2019-08-13/gh/fijk/png-rs:/opt/crater/workdir:ro,Z" "-v" "/mnt/big/crater/work/local/cargo-home:/opt/crater/cargo-home:ro,Z" "-v" "/mnt/big/crater/work/local/rustup-home:/opt/crater/rustup-home:ro,Z" "-e" "USER_ID=1000" "-e" "SOURCE_DIR=/opt/crater/workdir" "-e" "MAP_USER_ID=1000" "-e" "CARGO_TARGET_DIR=/opt/crater/target" "-e" "CARGO_INCREMENTAL=0" "-e" "RUST_BACKTRACE=full" "-e" "RUSTFLAGS=--cap-lints=warn" "-e" "CARGO_HOME=/opt/crater/cargo-home" "-e" "RUSTUP_HOME=/opt/crater/rustup-home" "-w" "/opt/crater/workdir" "-m" "1536M" "--network" "none" "rustops/crates-build-env" "/opt/crater/cargo-home/bin/cargo" "+beta-2019-08-13" "build" "--frozen"`
[INFO] [stdout] 0a9d20f34ac6da8cfa24bb8b3ca0c0fdd12655f6843b345d6fb7c0bc53055edd
[INFO] running `"docker" "start" "-a" "0a9d20f34ac6da8cfa24bb8b3ca0c0fdd12655f6843b345d6fb7c0bc53055edd"`
[INFO] [stderr]    Compiling png-rs v0.1.0 (/opt/crater/workdir)
[INFO] [stderr] warning: unused import: `std::iter::FromIterator`
[INFO] [stderr]    --> src/lib.rs:140:9
[INFO] [stderr]     |
[INFO] [stderr] 140 |                 use std::iter::FromIterator;
[INFO] [stderr]     |                     ^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr]     |
[INFO] [stderr]     = note: `#[warn(unused_imports)]` on by default
[INFO] [stderr] 
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]    --> src/lib.rs:198:23
[INFO] [stderr]     |
[INFO] [stderr] 198 |                 self.data.len() * 3 as u32
[INFO] [stderr]     |                                   ^^^^^^^^ expected usize, found u32
[INFO] [stderr] 
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]    --> src/lib.rs:198:5
[INFO] [stderr]     |
[INFO] [stderr] 197 |             fn length(&self) -> u32 {
[INFO] [stderr]     |                                 --- expected `u32` because of return type
[INFO] [stderr] 198 |                 self.data.len() * 3 as u32
[INFO] [stderr]     |                 ^^^^^^^^^^^^^^^^^^^^^^^^^^ expected u32, found usize
[INFO] [stderr] help: you can convert an `usize` to `u32` and panic if the converted value wouldn't fit
[INFO] [stderr]     |
[INFO] [stderr] 198 |                 (self.data.len() * 3 as u32).try_into().unwrap()
[INFO] [stderr]     |
[INFO] [stderr] 
[INFO] [stderr] error[E0277]: cannot multiply `u32` to `usize`
[INFO] [stderr]    --> src/lib.rs:198:21
[INFO] [stderr]     |
[INFO] [stderr] 198 |                 self.data.len() * 3 as u32
[INFO] [stderr]     |                                 ^ no implementation for `usize * u32`
[INFO] [stderr]     |
[INFO] [stderr]     = help: the trait `std::ops::Mul<u32>` is not implemented for `usize`
[INFO] [stderr] 
[INFO] [stderr] error[E0308]: mismatched types
[INFO] [stderr]    --> src/lib.rs:201:30
[INFO] [stderr]     |
[INFO] [stderr] 201 |             fn from(data: Vec<u8>) -> Self {
[INFO] [stderr]     |                ----                   ^^^^ expected struct `format::chunks::PaletteChunk`, found ()
[INFO] [stderr]     |                |
[INFO] [stderr]     |                implicitly returns `()` as its body has no tail or `return` expression
[INFO] [stderr]     |
[INFO] [stderr]     = note: expected type `format::chunks::PaletteChunk`
[INFO] [stderr]                found type `()`
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to 4 previous errors
[INFO] [stderr] 
[INFO] [stderr] Some errors have detailed explanations: E0277, E0308.
[INFO] [stderr] For more information about an error, try `rustc --explain E0277`.
[INFO] [stderr] error: Could not compile `png-rs`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "0a9d20f34ac6da8cfa24bb8b3ca0c0fdd12655f6843b345d6fb7c0bc53055edd"`
[INFO] running `"docker" "rm" "-f" "0a9d20f34ac6da8cfa24bb8b3ca0c0fdd12655f6843b345d6fb7c0bc53055edd"`
[INFO] [stdout] 0a9d20f34ac6da8cfa24bb8b3ca0c0fdd12655f6843b345d6fb7c0bc53055edd