Function _write_zccache_input_sidecar

ci/meson/meson_setup_execute.py:423–456

Persist FastLED's source/test/example hashes to a sidecar file the zccache configure-cache wrapper can hash via ``--input-file``. The sidecar lives in ``build_dir.parent`` (typically ``.build/``) so it survives ``bash test --clean`` (which wipes the inner build dir but leaves ``.bui

(
    *,
    build_dir: Path,
    build_mode: str,
    source_hashes: "SourceHashes",
)

def _write_zccache_input_sidecar(
    *,
    build_dir: Path,
    build_mode: str,
    source_hashes: "SourceHashes",
) -> Optional[Path]:
    """Persist FastLED's source/test/example hashes to a sidecar file the
    zccache configure-cache wrapper can hash via ``--input-file``.

    The sidecar lives in ``build_dir.parent`` (typically ``.build/``) so
    it survives ``bash test --clean`` (which wipes the inner build dir
    but leaves ``.build/`` intact). The per-build-mode suffix prevents
    cross-mode cache pollution. Returns the sidecar path on success or
    ``None`` if the parent isn't writable (in which case the caller
    falls back to the non-input-file wrapper invocation).
    """
    sidecar_dir = build_dir.parent
    try:
        sidecar_dir.mkdir(parents=True, exist_ok=True)
    except OSError:
        return None
    sidecar = sidecar_dir / f".zccache-meson-inputs-{build_mode}.hash"
    payload = "\n".join(
        [
            f"src={source_hashes.src_hash}",
            f"test={source_hashes.test_hash}",
            f"source={source_hashes.source_hash}",
        ]
    )
    try:
        sidecar.write_text(payload, encoding="utf-8")
    except OSError:
        return None
    return sidecar


def build_meson_setup_cmd(