Resolving Homebrew Errors on macOS 26 Beta

If you’re an early adopter who enjoys installing Apple’s latest beta software right after WWDC announcements, you might encounter compatibility issues with some of your essential development tools. One common issue on macOS 26 Beta is encountering Homebrew errors when trying to uninstall packages:

/opt/homebrew/Library/Homebrew/macos_version.rb:53:in `MacOSVersion#initialize': unknown or unsupported macOS version: "26.0" (MacOSVersion::Error)

Here’s a straightforward guide to resolve this:

Why This Error Occurs

Homebrew maintains an internal list of supported macOS versions. When Apple releases a new beta, Homebrew might not immediately recognize it, causing commands like brew uninstall to fail.

Quick Fix: Update Homebrew

The simplest initial step is updating Homebrew to fetch recent changes that support the new macOS version:

brew update-reset

This command refreshes your Homebrew installation, which often fixes compatibility issues.

If Updating Doesn’t Work

If the quick update doesn’t resolve the issue, here are alternative methods:

1. Unset Compatibility Variable

Some developers find success by unsetting the SYSTEM_VERSION_COMPAT environment variable:

unset SYSTEM_VERSION_COMPAT

Try running your Homebrew command again after this.

2. Manually Remove the Package

If Homebrew remains unusable, manually remove the problematic package. For instance, to remove supabase:

rm -rf /opt/homebrew/Cellar/supabase
rm /opt/homebrew/bin/supabase

Note: This method doesn’t handle dependencies or metadata cleanup, but effectively removes the specific package.

3. Completely Uninstall Homebrew

As a last resort, if you need a clean start:

/bin/bash -c "$(curl -fsSL https://raw.githubusercontent.com/Homebrew/install/HEAD/uninstall.sh)"

If this script fails due to the same compatibility error, manually remove Homebrew:

sudo rm -rf /opt/homebrew

Ensure to backup important configurations before proceeding.

Recommendation

• For minimal disruption, first try updating Homebrew.
• If urgent package removal is needed, manual removal is effective.
• Avoid installing beta versions if your workflow critically depends on Homebrew stability.

Always back up essential data and configurations before attempting these steps.