Worried about the continued support to diffmerge in macOS 26.4 (newest as of April 2026)

[lumeng]

I'd like to bring to the attention of DiffMerge developers and/or the product manager that in the newest macOS (26.4) as of April, 2026,

* Installation of DiffMerge via Homebrew still works, but is marked as Deprecated!

* After installing, macOS sends a warning in the Notification Center that DiffMerge "will no longer open in newer version of macOS" possibly due to the build being only available for old and obsoleting Intel chips, but NOT the newer "Apple Silicon" M* chips.

See

* terminal output for installing DiffMerge via Homebrew:

Code: Select all

$ brew search diffmerge
==> Formulae
diffr

==> Casks
diffmerge ✔ (deprecated)

$ brew install diffmerge
==> Auto-updating Homebrew...
Adjust how often this is run with `$HOMEBREW_AUTO_UPDATE_SECS` or disable with
`$HOMEBREW_NO_AUTO_UPDATE=1`. Hide these hints with `$HOMEBREW_NO_ENV_HINTS=1` (see `man brew`).
==> Auto-updated Homebrew!
Updated 2 taps (homebrew/core and homebrew/cask).
...
==> Fetching downloads for: diffmerge
Warning: diffmerge has been deprecated because it does not pass the macOS Gatekeeper check! It will be disabled on 2026-09-01.
✔︎ Cask diffmerge (4.2.1.1013)                                                                                                                   Verified     10.8MB/ 10.8MB
Warning: diffmerge has been deprecated because it does not pass the macOS Gatekeeper check! It will be disabled on 2026-09-01.
==> Caveats
diffmerge is built for Intel macOS and so requires Rosetta 2 to be installed.
You can install Rosetta 2 with:
  softwareupdate --install-rosetta --agree-to-license
Note that it is very difficult to remove Rosetta 2 once it is installed.

==> Installing Cask diffmerge
==> Moving App 'DiffMerge.app' to '/Applications/DiffMerge.app'
==> Linking Binary 'diffmerge.sh' to '/opt/homebrew/bin/diffmerge'
==> Linking Manpage 'diffmerge.1' to '/opt/homebrew/share/man/man1/diffmerge.1'
🍺  diffmerge was successfully installed!

$ softwareupdate --install-rosetta --agree-to-license
By using the agreetolicense option, you are agreeing that you have run this tool with the license only option and have read and agreed to the terms.
If you do not agree, press CTRL-C and cancel this process immediately.
2026-04-10 11:05:50.351 softwareupdate[10701:236577] Package Authoring Error: 122-10754: Package reference com.apple.pkg.RosettaUpdateAuto is missing installKBytes attribute
Install of Rosetta 2 finished successfully

DiffMerge is a great piece of software. If possible, please address these issues so users can be rest assured that DiffMerge continues to work.

[Tonya]

Hello,

We are currently transitioning DiffMerge into an open source project. There is a build available on GitHub if you are interested:

https://github.com/sourcegear/diffmerge ... g/v5.0.0.1

Please note, this is still an ongoing transition and we are still working on the progress.

Moving forward, any information you'd like to provide (bugs, enhancements, etc) should be submitted through GitHub.

Thanks,

Tonya

[lumeng]

Great to know that. Can you make it work without warnings in Homebrew as well? At the moment it warns that diffmerge is deprecated:

Code: Select all

$ brew upgrade diffmerge
$ brew doctor
Warning: Some installed casks are deprecated or disabled.
You should find replacements for the following casks:
  diffmerge

[Tonya]

Hello again,

Any information you'd like to provide (bugs, enhancements, etc) should be submitted through GitHub.

Tonya