Migration Assistant with Homebrew

[johnalanwoods]

Output of brew config

: 4.5.10
ORIGIN: https://github.com/Homebrew/brew
HEAD: 23c491e5bc9bfef218356c54e3b8971fbcc9ff13
Last commit: 4 days ago
Branch: stable
Core tap JSON: 17 Jul 09:57 UTC
Core cask tap JSON: 17 Jul 09:59 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_CASK_OPTS: []
HOMEBREW_MAKE_JOBS: 14
Homebrew Ruby: 3.4.4 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/3.4.4/bin/ruby
CPU: 14-core 64-bit arm_brava
Clang: 17.0.0 build 1700
Git: 2.50.1 => /opt/homebrew/bin/git
Curl: 8.7.1 => /usr/bin/curl
macOS: 15.5-arm64
CLT: 26.0
Xcode: 16.4
Rosetta 2: false

Output of brew doctor

note that these warnings are just used to help the Homebrew maintainers
with debugging if you file an issue. If everything you use Homebrew for is
working fine: please don't worry or file an issue; just ignore this. Thanks!

Warning: Some installed formulae are deprecated or disabled.
You should find replacements for the following formulae:
  icu4c@76
  libgit2@1.7
  six

Warning: The following formulae have the same name as core formulae:
  blacktop/tap/go
  blacktop/tap/ipsw
  blacktop/tap/syft
  rs/tap/curlie
Their taps are in use, so you must use these full names throughout Homebrew.

Description of issue

I appreciate that I can use brew bundle to migrate my formula/casks from one machine to another, but more generally, Apple's Migration Assistant seems to work migrating my large homebrew environment.

From Apple Silicon device to Apple Silicon device, are there any gotchas when migrating Hombrew installs via Migration Assistant that would necessitate the use of brew bundle? - or is Migration Assistant enough?

It seems that even ad-hoc signed bottles work OK!

[SMillerDev]

From Apple Silicon device to Apple Silicon device, are there any gotchas when migrating Hombrew installs via Migration Assistant that would necessitate the use of brew bundle? - or is Migration Assistant enough?

Migration Assistant will move your intel install of Homebrew, so you're running everything in Rosetta after. brew bundle will install the native versions of all tools.

[johnalanwoods]

Hey @SMillerDev - thanks for the reply.

I’m moving from a purely ARM64 only Apple Silcon device to another Apple Silicon device, no Intel install. Source install is /opt.

It seems to be working but was wondering if there are any gotchas or if Migration Assistant would move the entire environment/homebrew intact?

[gromgit]

AS-to-AS migrations of Homebrew and installed formulae/casks should be seamless, but depending on how big a jump is made in macOS versions, you may have to reinstall some formulae that are system-version sensitive for whatever reason.

[johnalanwoods]

Gotcha. The macOS versions are matched exactly.

So I guess this is as good as a manual install on the new machine and brew bundle dump? There’s no gotcha or parts of homebrew that wouldn’t be ported?

[gromgit]

Considering that Homebrew works very hard to confine its own I/O operations¹ under $HOMEBREW_PREFIX, I'd say yes. If there's a functional difference somewhere, something probably went wrong with the migration itself.

Footnotes

1. This excludes brew services and cask binaries in /Applications and elsewhere, both of which involve system/3rd-party I/O. ↩

[johnalanwoods]

Thanks @gromgit - services and cask apps seem to have come over properly too. Anything extra I need to do with them? Or is that footnote just a technical point and indeed services and casks migrate fine too - ie would run / update fine etc?

[gromgit]

Definitely check whether the services you previously configured to launch on login still do so on your new box.

Casks are basically black boxes to Homebrew; whether the underlying installations survived migration is dependent on what the upstream installers do on your system. I've yet to do an AS-to-AS migration myself, but one of the first things I'd check when I have to do it is whether I have to grant permissions to macFUSE on the new box, as if I'd just installed it brand-new. (Even then, I'd probably manually reinstall it, just to be sure.)