Fix: don't fail link check on transient connection failures

[Aetf]

Why this matters more than it looks

The link check is why CI on develop has been red, and that had a real consequence: it blocked Renovate's automerge, so hexo-theme-next never advanced past 8.24.0 — the exact release that blanked the site.

Renovate opened a PR with the fix (#44) on 2025-09-06. It sat unmerged for eleven months and was autoclosed today, only because #54 landed the bump by hand. The develop run history tells the same story:

success  2026-08-06  Fix: update hexo-theme-next to v8.29.0 ...   <- manual
failure  2025-12-29  Update actions/cache action to v5
failure  2025-12-29  Update actions/checkout action to v6
failure  2025-12-29  Migrate config renovate.json
success  2025-08-09  Update dependency hexo-theme-next to v8.24.0  <- the deploy that broke the site

The failure mode

A crawl of ~5900 links hits a couple of hundred external hosts within a few seconds. From GitHub Actions runners some of them intermittently refuse the connection:

210 https://hexo.io/ (connection failed)
 12 https://letsencrypt.org/ (connection failed)
  2 https://www.mosharaf.com (connection failed)

hexo.io dominates because the theme footer links it from every page, so a single refusal becomes 210 reported failures. All three resolve fine from anywhere else — I checked each by hand. The existing retry loop can't absorb it either: its 5 attempts all land inside the same ~45 second window.

The fix

Use linkcheck's own --connection-failures-as-warnings, and treat a warnings-only run as a pass. That second half is necessary — linkcheck exits 2 on errors, 1 on warnings-only, 0 when clean, so the flag alone still leaves a nonzero exit. The wrapper now maps 1 to success.

This does not weaken the check

Real HTTP errors stay fatal. Verified both directions against a local fixture:

fixture	result
good link + refused connection	1 warning, 0 errors, exit 0
the same plus one genuine 404	1 warning, 1 error, exit 2

The Deep Blue 403 dealt with in 820f4c1 is an HTTP status, not a connection failure, so it would still fail today — which is why that skip entry stays.

Note

#55 and #56 are currently blocked on exactly this flake and should go green once this lands and they're rebased.

🤖 Generated with Claude Code