macOS 26 breaks custom DNS settings including .internal

Original Article ↗ Hacker News Discussion ↗

macOS 26 appears to have broken long‑standing support for custom DNS resolution (e.g., `/etc/resolver` entries and private TLDs such as `.internal`), disrupting workflows that rely on tools like dnsmasq, Docker, and homelab setups. Commenters share mixed experiences—some seeing no issues with specific resolver configurations, others forced back to `/etc/hosts` or alternative domains like `*.localhost`—and debate Apple’s growing tendency to ship breaking changes that particularly hurt developers. The thread also branches into broader critiques of macOS reliability, networking quirks, and the use of large language models to generate bug reports, raising concerns about trust, accuracy, and QA across the platform.

DNS and macOS 26 Regression

  • macOS 26 appears to break custom DNS setups that rely on /etc/resolver, especially for private TLDs like .internal, .local, .home.arpa, etc.
  • Some note /etc/resolver has been considered deprecated for years; Apple seems to be phasing it out in favor of scutil-managed config and mDNSResponder.
  • Others report no issues with similar setups when domain is specified in resolver files, suggesting configuration details may matter.
  • There is disagreement over scope: some say .test and other custom TLDs still work when configured via Apple’s container DNS tooling; others say they’re now unreliable.

Workarounds and Alternatives

  • Short-term workaround: use /etc/hosts entries, but this is seen as impractical for dynamic cases (e.g., Docker, containers).
  • Suggestions include:
    • Using scutil and/or running a local DNS server like unbound or dnsmasq.
    • Offloading DNS to Pi-hole or similar network appliances.
    • Switching to *.localhost (and even *.*.localhost) for browser-based local dev; this works seamlessly in modern browsers and, according to some, also via system DNS in Tahoe, but others report browser-only behavior.
    • Using external helper domains like lvh.me or nip.io that resolve to loopback or chosen IPs.

macOS Quality, UX, and Breaking Changes

  • Many view macOS 26 as especially breaking for developers: DNS behavior, UI changes (“Tahoe” rounded windows, resize handles), restrictions on display brightness APIs, microphone indicator dimming, and various app breakages.
  • Others say Tahoe works fine for them and criticize selection bias; they argue people primarily post when something breaks.
  • Ongoing frustration with Apple’s willingness to break backward compatibility (vs. Microsoft’s reputation for preserving it) is contrasted with the reality that all major OSes have similar “papercuts.”

Containers, Networking, and Ports

  • Apple’s container system is described as fragile around DNS, prompting some to abandon it; open GitHub issues on container DNS are cited.
  • macOS system services occupying higher ports like 8080 and 5000 (e.g., when Screen Time is enabled) surprise developers and can break tooling (e.g., apt-get in Docker builds due to modified traffic).

AI/LLM-Generated Bug Reports

  • Several commenters criticize the linked bug report as obviously LLM-written (e.g., references to non-existent “macOS 25” and auto major-version upgrades).
  • Concerns:
    • Reviewers may start discarding LLM-flavored reports due to trust and validation overhead.
    • AI-generated text is often verbose, can hallucinate facts, and may not reflect the author’s real understanding.
  • Broader ethical debate:
    • Some say non-disclosed LLM use is disrespectful to readers and erodes trust.
    • Others argue LLMs can help non-native speakers or weak writers but insist on human review and ownership.
    • There is disagreement on where to draw the line (proofreading, drafting, documentation, legal/medical writing, etc.).