Thank you for reporting this issue to Unity.
We attempted to reproduce the Unity CLI installation failure on Intel macOS Sequoia 15.7.7 (x86_64) using the exact command provided:
curl -fsSL https://public-cdn.cloud.unity3d.com/hub/prod/cli/install.sh | UNITY_CLI_CHANNEL=beta bash
The installer completed successfully, downloading and verifying Unity CLI 0.1.0-beta.4 for darwin-x64 without errors. Since the original report, the issue is no longer reproducible - this may have been caused by a transient CDN, network, or checksum-verification condition at the time of the original attempt that has since been resolved.