`homebrew/autoupdate` tap causes a `deprecated "master"` warning

[yurikoles]

brew doctor output

Please 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 casks are deprecated or disabled.
You should find replacements for the following casks:
  deadbeef@nightly
  dupeguru
  mkvtoolnix-app
  provisionql
  qlcolorcode
  qlstephen
  quicklookase
  rar
  smplayer
  stolendata-mpv
  syntax-highlight
  webpquicklook
  whoozle-android-file-transfer

Warning: Some installed kegs have no formulae!
This means they were either deleted or installed manually.
You should find replacements for the following formulae:
  openssl@1.1

Warning: Some installed formulae are deprecated or disabled.
You should find replacements for the following formulae:
  git-flow
  sshfs-mac
  icu4c@77
  libsass
  openssl@1.1
  pidof
  speedtest-cli

Warning: Putting non-prefixed coreutils in your path can cause GMP builds to fail.

Warning: The following repositories are on the deprecated "master" branch.
The "master" branch sync will stop and this warning will become an error
when Homebrew 5.2.0 is released (no earlier than 2026-06-10).
Run `brew update` to migrate to "main":
  homebrew/autoupdate

Verification

• I ran brew update twice and am still able to reproduce my issue.
• My "brew doctor output" above says Your system is ready to brew or a definitely unrelated Tier message.
• This issue's title and/or description do not reference a single formula e.g. brew install wget. If they do, open an issue at https://github.com/Homebrew/homebrew-core/issues/new/choose instead.

brew config output

HOMEBREW_VERSION: 5.1.5-110-g0f46368
ORIGIN: https://github.com/Homebrew/brew
HEAD: 0f4636820f30526cdca89575676dfd6f5872204d
Last commit: 12 hours ago
Branch: main
Core tap HEAD: bdf5ccca660b2f9f69b38687c8514d8b93423fe1
Core tap last commit: 23 minutes ago
Core tap JSON: 12 Apr 13:28 UTC
Core cask tap HEAD: b5ccca7aa6395b03f33ed17d525d369ff8af94e1
Core cask tap last commit: 27 minutes ago
Core cask tap JSON: 12 Apr 13:28 UTC
HOMEBREW_PREFIX: /opt/homebrew
HOMEBREW_API_AUTO_UPDATE_SECS: 300
HOMEBREW_AUTO_UPDATE_SECS: 300
HOMEBREW_CASK_OPTS: ["--no-quarantine"]
HOMEBREW_DEVELOPER: set
HOMEBREW_DOWNLOAD_CONCURRENCY: 32
HOMEBREW_EDITOR: zed -w
HOMEBREW_FORCE_BREWED_CURL: set
HOMEBREW_FORCE_BREWED_GIT: set
HOMEBREW_GITHUB_API_TOKEN: set
HOMEBREW_MAKE_JOBS: 8
HOMEBREW_SORBET_RUNTIME: set
HOMEBREW_UPGRADE_AUTO_UPDATES_CASKS: set
HOMEBREW_UPGRADE_GREEDY: set
Homebrew Ruby: 4.0.2 => /opt/homebrew/Library/Homebrew/vendor/portable-ruby/4.0.2_1/bin/ruby
CPU: octa-core 64-bit arm_firestorm_icestorm
Clang: 21.0.0 build 2100
Git: 2.53.0 => /opt/homebrew/opt/git/bin/git
Curl: 8.19.0 => /opt/homebrew/opt/curl/bin/curl
macOS: 26.4.1-arm64
CLT: 26.4.0.0.1774242506
Xcode: 26.4 => /Applications/Xcode_26.4.app/Contents/Developer
Metal Toolchain: N/A
Rosetta 2: false

What were you trying to do (and why)?

Continue to use Homebrew without the errors that are introduced by and can be mitigated by its maintainers.

The tap's repo has moved from the Homebrew namespace umbrella homebrew/autoupdate to a domt4/autoupdate, so GitHub made a valid redirect. And the brew doctor output wording is confusing users that the official tap isn't migrated to a master branch.

Warning: The following repositories are on the deprecated "master" branch.
The "master" branch sync will stop and this warning will become an error
when Homebrew 5.2.0 is released (no earlier than 2026-06-10).
Run `brew update` to migrate to "main":
  homebrew/autoupdate

See DomT4/homebrew-autoupdate#220

What happened (include all command output)?

$ brew tap homebrew/autoupdate             
zsh: correct 'homebrew/autoupdate' to '.homebrew/autoupdate' [nyae]? n
==> Tapping homebrew/autoupdate
Cloning into '/opt/homebrew/Library/Taps/homebrew/homebrew-autoupdate'...
remote: Enumerating objects: 1859, done.
remote: Counting objects: 100% (430/430), done.
remote: Compressing objects: 100% (145/145), done.
remote: Total 1859 (delta 323), reused 298 (delta 281), pack-reused 1429 (from 3)
Receiving objects: 100% (1859/1859), 569.37 KiB | 8.90 MiB/s, done.
Resolving deltas: 100% (879/879), done.
Tapped 1 command (42 files, 974.3KB).

$ brew doctor
<see above>

What did you expect to happen?

Taps under Homebrew's GitHub organisation umbrella shouldn't trigger brew doctor.

Step-by-step reproduction instructions (by running brew commands)

brew tap homebrew/autoupdate

[MikeMcQuaid]

brew untap homebrew/autoupdate and retap it with the new/correct remote.