M4 Macs can't virtualise older macOS

Original Article ↗ Hacker News Discussion ↗

Apple’s approach to backward compatibility

  • Many see Apple as consistently willing to drop old software/hardware support (PPC, 32‑bit, OpenGL, older macOS/iOS) in ways that break existing apps and games.
  • Others note Apple still leads in long official device support and aftermarket life, but agree post‑support compatibility is not a major priority.
  • Some argue this is rational: Apple optimizes for new hardware sales and simplicity, and is comfortable losing users who won’t adapt.

Virtualizing older macOS / iOS and 32-bit software

  • The article’s finding that M4 Macs can’t virtualize macOS < 13.4 is seen as a serious regression for devs and testers.
  • Use cases cited: CI, cross‑version QA, debugging behavior on older macOS, and niche tasks that require old system behavior.
  • On iOS, some wish they could run old 32‑bit apps in sandboxed containers; others point out AArch32 support is gone in hardware, so only heavy emulation is possible.
  • There’s debate over security and maintenance: keeping old OSes around, even sandboxed, increases attack surface and testing burden.

Bug vs intentional decision

  • Some commenters say Apple staff have called the M4 limitation an unintentional bug; others doubt this or can’t verify due to closed bug tracker access.
  • Another view is that documentation and Apple’s QA model (only guaranteeing the shipped OS) suggest this is intentional: they don’t want to support older guests on new chips.
  • Several expect low priority for any fix, since those macOS versions are now EOL.

Impact on development, CI, and containers

  • macOS is criticized as uniquely painful for CI: no native container tech comparable to Linux or Windows, restrictive licensing (only 2 macOS VMs per host), and reliance on third‑party tools.
  • Workarounds exist (VM products, Darwin containers, cross‑compilers), but people expect Apple to shut down anything that reduces hardware demand.
  • Some note Rosetta and virtualization have been a strength, but incompatibilities (e.g., missing newer x86‑64 instruction sets) already constrain build optimization.

Gaming and ecosystem comparisons

  • Several connect this to a broader pattern: deprecating OpenGL, Metal‑only strategy, and uncertain Rosetta future pushing games and some pro apps away from macOS.
  • Comparisons highlight Windows’ strong backward compatibility and Linux’s fragmented ABI situation, with trade‑offs in stability vs evolution.