Velox UT failed on Mac env

[zhouyuan]

Hi, I’ve noticed that a few unit tests fail on macOS. Some of these issues seem to stem from differences between macOS and Linux implementations — for example, floating-point precision and certain system APIs like timegm. I also saw that these tests are skipped in Mac CI (https://github.com/facebookincubator/velox/blob/main/.github/workflows/macos.yml#L126).

Does this suggest that we should consider moving to a Linux-based environment instead?

Thanks, -Yuan

[cookesan]

If your goal is full unit-test parity with the project CI signal, Linux is the safer environment.

Velox documents macOS as a supported development/build environment, but the macOS workflow you linked skips the explicit test step. That means "builds on macOS" and "the full unit suite is expected to pass on macOS exactly like Linux" are not the same guarantee. Differences around libc/system APIs such as timegm and floating-point behavior are plausible platform issues rather than necessarily local setup mistakes.

I would use Linux or a Linux container/VM for the authoritative test run, especially before sending changes. macOS is still useful for development/build checks, but if a macOS-only unit failure matters, it is worth reporting as a specific platform failure with the exact test, compiler, and dependency versions instead of treating it as the main pass/fail baseline.