The non-required **Unified Agent Native Verification** workflow has
failed on `main` (and most PRs) in both macOS jobs since 12 Oct (first
failing main run 38285211868 on c3524d373a; last green 38273335159 on
552e838749). The single cause is
`TestInstallSHUpstartTeardownRequiresObservedQuiescence`: 13 Python
subtests in `agent_upstart_teardown.py` fail with `ln: illegal option --
T`.
`scripts/install.sh` uses `ln -T -- <pending> <override>` and `ln -T --
<retired> <conf>` in the DSM Upstart teardown (added in the DSM
retirement series, a7271f5840 / b7b0eb0b01). That path only runs on
Synology DSM (Linux), so the installer is correct. The harness runs
those functions with the host `ln`, which on macOS runners is BSD `ln`
without `-T`.
The workflow already supplies GNU `stat/chmod/chown/mv/tar` (plus Bash
5) for Linux-only installer fixtures on macOS. This adds `ln` to that
set and extends `TestNativeInstallerFixtureToolsAreRealAndStepLocal` to
require it (missing/non-GNU scenarios, PATH binding, and real `ln -T`
no-replacement checks against file and directory targets).
Verification:
- Reproduced locally on macOS: the harness fails 13/15 with BSD `ln` and
passes 15/15 when `ln -T` is available.
- `TestNativeInstallerFixtureToolsAreRealAndStepLocal`: fails against
the old workflow (real tools, missing ln, non-GNU ln) and passes with
this change (Linux).
- The macOS jobs themselves are only exercised by this PR's CI run.
rcourtman
cce5ca2a7e