[INFO] updating cached repository https://github.com/twe4ked/mandelbrot-set
[INFO] running `"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"`
[INFO] running `"git" "rev-parse" "HEAD"`
[INFO] [stdout] 4f38f2bd88d4146dfe2fe049c93b126872f673af
[INFO] checking twe4ked/mandelbrot-set against master#209b2be09fcaff937480d1fbbe8b31646e361c7a for pr-70917
[INFO] running `"git" "clone" "/workspace/cache/git-repos/https%3A%2F%2Fgithub.com%2Ftwe4ked%2Fmandelbrot-set" "/workspace/builds/worker-4/source"`
[INFO] [stderr] Cloning into '/workspace/builds/worker-4/source'...
[INFO] [stderr] done.
[INFO] validating manifest of git repo https://github.com/twe4ked/mandelbrot-set on toolchain 209b2be09fcaff937480d1fbbe8b31646e361c7a
[INFO] running `"/workspace/cargo-home/bin/cargo" "+209b2be09fcaff937480d1fbbe8b31646e361c7a" "read-manifest" "--manifest-path" "Cargo.toml"`
[INFO] started tweaking git repo https://github.com/twe4ked/mandelbrot-set
[INFO] finished tweaking git repo https://github.com/twe4ked/mandelbrot-set
[INFO] tweaked toml for git repo https://github.com/twe4ked/mandelbrot-set written to /workspace/builds/worker-4/source/Cargo.toml
[INFO] crate git repo https://github.com/twe4ked/mandelbrot-set already has a lockfile, it will not be regenerated
[INFO] running `"/workspace/cargo-home/bin/cargo" "+209b2be09fcaff937480d1fbbe8b31646e361c7a" "fetch" "--locked" "--manifest-path" "Cargo.toml"`
[INFO] running `"docker" "create" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/target:/opt/rustwide/target:rw,Z" "-v" "/var/lib/crater-agent-workspace/builds/worker-4/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=forbid" "-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" "/opt/rustwide/cargo-home/bin/cargo" "+209b2be09fcaff937480d1fbbe8b31646e361c7a" "check" "--frozen" "--all" "--all-targets"`
[INFO] [stderr] WARNING: Your kernel does not support swap limit capabilities or the cgroup is not mounted. Memory limited without swap.
[INFO] [stdout] 1a73b8afa09f3552faab0499faa23e06e0b3e5ac8f01f47e65016c8311ab59ce
[INFO] running `"docker" "start" "-a" "1a73b8afa09f3552faab0499faa23e06e0b3e5ac8f01f47e65016c8311ab59ce"`
[INFO] [stderr]    Compiling num-complex v0.2.1
[INFO] [stderr]     Checking png v0.16.1
[INFO] [stderr]     Checking mandelbrot-set v0.1.0 (/opt/rustwide/workdir)
[INFO] [stderr] warning: struct is never constructed: `Buffer`
[INFO] [stderr]  --> src/buffer.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub struct Buffer {
[INFO] [stderr]   |            ^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]  --> src/buffer.rs:8:5
[INFO] [stderr]   |
[INFO] [stderr] 8 |     pub fn new(width: usize, height: usize) -> Self {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_pixel`
[INFO] [stderr]   --> src/buffer.rs:17:5
[INFO] [stderr]    |
[INFO] [stderr] 17 |     pub fn set_pixel(&mut self, x: usize, y: usize, color: u32) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `buffer`
[INFO] [stderr]   --> src/buffer.rs:33:5
[INFO] [stderr]    |
[INFO] [stderr] 33 |     pub fn buffer(&self) -> &[u8] {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: struct is never constructed: `Buffer`
[INFO] [stderr]  --> src/buffer.rs:1:12
[INFO] [stderr]   |
[INFO] [stderr] 1 | pub struct Buffer {
[INFO] [stderr]   |            ^^^^^^
[INFO] [stderr]   |
[INFO] [stderr]   = note: `#[warn(dead_code)]` on by default
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `new`
[INFO] [stderr]  --> src/buffer.rs:8:5
[INFO] [stderr]   |
[INFO] [stderr] 8 |     pub fn new(width: usize, height: usize) -> Self {
[INFO] [stderr]   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `set_pixel`
[INFO] [stderr]   --> src/buffer.rs:17:5
[INFO] [stderr]    |
[INFO] [stderr] 17 |     pub fn set_pixel(&mut self, x: usize, y: usize, color: u32) {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] warning: method is never used: `buffer`
[INFO] [stderr]   --> src/buffer.rs:33:5
[INFO] [stderr]    |
[INFO] [stderr] 33 |     pub fn buffer(&self) -> &[u8] {
[INFO] [stderr]    |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0603]: module `buffer` is private
[INFO] [stderr]  --> src/main.rs:1:21
[INFO] [stderr]   |
[INFO] [stderr] 1 | use mandelbrot_set::buffer::Buffer;
[INFO] [stderr]   |                     ^^^^^^ private module
[INFO] [stderr]   |
[INFO] [stderr] note: the module `buffer` is defined here
[INFO] [stderr]  --> /opt/rustwide/workdir/src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | mod buffer;
[INFO] [stderr]   | ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error[E0603]: module `buffer` is private
[INFO] [stderr]  --> src/main.rs:1:21
[INFO] [stderr]   |
[INFO] [stderr] 1 | use mandelbrot_set::buffer::Buffer;
[INFO] [stderr]   |                     ^^^^^^ private module
[INFO] [stderr]   |
[INFO] [stderr] note: the module `buffer` is defined here
[INFO] [stderr]  --> /opt/rustwide/workdir/src/lib.rs:1:1
[INFO] [stderr]   |
[INFO] [stderr] 1 | mod buffer;
[INFO] [stderr]   | ^^^^^^^^^^^
[INFO] [stderr] 
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0603`.
[INFO] [stderr] error: could not compile `mandelbrot-set`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] [stderr] warning: build failed, waiting for other jobs to finish...
[INFO] [stderr] error: aborting due to previous error
[INFO] [stderr] 
[INFO] [stderr] For more information about this error, try `rustc --explain E0603`.
[INFO] [stderr] error: could not compile `mandelbrot-set`.
[INFO] [stderr] 
[INFO] [stderr] To learn more, run the command again with --verbose.
[INFO] running `"docker" "inspect" "1a73b8afa09f3552faab0499faa23e06e0b3e5ac8f01f47e65016c8311ab59ce"`
[INFO] running `"docker" "rm" "-f" "1a73b8afa09f3552faab0499faa23e06e0b3e5ac8f01f47e65016c8311ab59ce"`
[INFO] [stdout] 1a73b8afa09f3552faab0499faa23e06e0b3e5ac8f01f47e65016c8311ab59ce
