Companion glibc 2.38+ floor: fix smoke env + document Linux/Intel-mac limits

[danieljhkim]

Task

ORB-00352 — Companion glibc 2.38+ floor: fix smoke env + document Linux/Intel-mac limits

Description

Problem

The semantic-search companion (ort 2.0.0-rc.12 / onnxruntime) has hard platform constraints surfaced during the v0.8.x release:

1. Linux companion requires glibc >= 2.38 at runtime. The smoke-install-ubuntu job in release.yml runs in an ubuntu:22.04 container (glibc 2.35), so it fails with 'version GLIBC_2.38 not found' when orbit semantic install executes the companion to download the model. This is a permanently-red leg by construction.
2. Intel macOS (x86_64-apple-darwin) has no companion at all (ort ships no prebuilt); orbit semantic install on Intel mac will fail trying to fetch a nonexistent asset.

Why It Matters

A permanently-red smoke leg erodes signal and the runbook expects all smoke jobs green. Users on glibc <2.38 Linux or Intel mac get raw loader/404 errors with no explanation of an unsupported platform.

Scope

1. Bump the smoke-install-ubuntu container from ubuntu:22.04 to ubuntu:24.04 (glibc 2.39) so it tests a supported env. Keep the CLI build on ubuntu-22.04.
2. Document the glibc >=2.38 Linux requirement and Intel-mac unsupported status for semantic search (docs/RELEASE.md + wherever orbit semantic install is described).
3. Make orbit semantic install emit a clean 'semantic search unsupported on this platform' message on Intel mac (platform_id macos-x86_64) and ideally a clear glibc-too-old hint on Linux, instead of a raw loader error or 404 (companion.rs / install.rs).

Acceptance Criteria

• release.yml smoke-install-ubuntu runs on ubuntu:24.04 and passes (companion executes, model downloads)
• docs state the Linux glibc >=2.38 requirement and Intel-mac unsupported status for the semantic companion
• orbit semantic install on Intel mac returns a clear unsupported-platform error rather than a 404 on a missing asset

Execution Summary

Click to expand

Outcome: success

Changes:

• Moved the release smoke-install-ubuntu job from Ubuntu 22.04 to Ubuntu 24.04, including the runner label and container image, while leaving Linux CLI release builds on Ubuntu 22.04.
• Added semantic companion platform support checks before default release-asset download selection. Intel macOS now returns semantic search unsupported on this platform (macos-x86_64) instead of constructing a missing companion URL, and GNU/Linux systems with detected glibc below 2.38 get a direct glibc floor message.
• Added focused orbit-search tests for released platforms, Intel macOS rejection, and the Linux glibc floor. Kept the checksum-manifest source test deterministic by avoiding current-host platform assumptions.
• Updated docs/RELEASE.md, README.md, and the packaged orbit-search skill docs to state the semantic companion support matrix: macOS arm64 and Linux x86_64/aarch64 with glibc >= 2.38; Intel macOS semantic search unsupported.

Assessment: The release smoke environment now matches the companion runtime floor, and unsupported install paths fail before network 404s with actionable messages.

Validation:

• cargo test -p orbit-search -- --quiet
• ruby -e 'require "yaml"; YAML.load_file(".github/workflows/release.yml")'
• git diff --check
• make ci-fast

Validation

• Not reported

Branch Freshness

• Base ref: origin/agent-main
• Head ref: orbit/ORB-00352-6a1be1a7
• Behind base: 0
• Ahead of base: 1