As commented in issues https://github.com/shssoichiro/oxipng/issues/444
and https://github.com/shssoichiro/oxipng/issues/518, there is some user
interest for distributing binaries for each unstable commit, and target
ARM64 platforms. Personally, I think both suggestions are useful for the
project, as uploading binary artifacts for each commit might help
interested users to catch regressions and give feedback earlier, and
powerful ARM64 platforms are becoming increasingly popular due to some
cloud services (e.g., Amazon EC2, Azure VMs, Oracle Cloud) offering
cheaper plans for this hardware, in addition to the well-known push for
ARM by Apple with their custom M1 chips.
These changes make the CI target ARM64 as a first-class citizen. Because
the public GitHub actions runners can only be hosted on x64 for now, I
resorted to cross-compilation, [Debian's
multiarch](https://elinux.org/images/d/d8/Multiarch_and_Why_You_Should_Care-_Running%2C_Installing_and_Crossbuilding_With_Multiple_Architectures.pdf),
and QEMU to build, get ARM64 C library dependencies, and run tests,
respectively.
When the CI workflow finishes, a release CLI binary artifact is now
uploaded, which can be downloaded from the workflow run page on the
GitHub web interface.
In addition, these changes also introduce some cleanup and miscellaneous
improvements and changes to the CI workflow:
- Tests are run using [`nextest`](https://nexte.st/) instead of `cargo
test`, which substantially speeds up their execution. (On my development
workstation, `cargo test --release` takes around 10.67 s, while `cargo
nextest run --release` takes around 6.02 s.)
- The dependencies on unmaintained `actions-rs` actions were dropped in
favor of running Cargo commands directly, or using
`giraffate/clippy-action` for pretty inline annotations for Clippy. This
gets rid of the deprecation warnings for each workflow run.
- Most CI steps are run with a nightly Rust toolchain now, which allows
to take advantage of the latest Clippy lints and codegen improvements.
In my experience, when not relying on specific nightly features or
compiler internals, Rust does a pretty good job at making it possible to
rely on a rolling-release compiler for CI, as breakage is extremely rare
and thus offset by the improved features.
- The MSRV check was moved to a separate job with less steps, so that it
takes less of a toll on total workflow run minutes.
## Pending tasks
- [x] Generate universal macOS binaries with `lipo` (i.e., containing
both `aarch64` and `x64` code)
- [x] Tirelessly fix the stupid errors that tend to happen when
deploying a new CI workflow for the first time
- [x] Think what to do with the `deploy.yml` workflow. Should it fetch
artifacts from the CI job instead of building them again?
- [x] Maybe bring back 32-bit Windows binaries. Are they actually useful
for somebody, or just a way to remember the good old days?
---------
Co-authored-by: Josh Holmer <jholmer.in@gmail.com>
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