Xcode Developer Tool Version Mismatch
How to fix Homebrew install failures caused by Xcode or Command Line Tools being too outdated.
Context#
- Environment:
- Having multiple Xcode installed (16.4 and 26.2)
- What I was doing:
- Installing Supabase CLI via Homebrew
The Error#
cii-intelligence git:feature/supabase-deployment*
❯ brew install supabase/tap/supabase
==> 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).
==> Fetching downloads for: supabase
✔︎ Formula supabase (2.75.0) Verified 28.1MB/ 28.1MB
==> Installing supabase from supabase/tap
Error: Your Xcode (16.4 => /Applications/Xcode_16.4.app/Contents/Developer) at /Applications/Xcode.app is too outdated.
Please update to Xcode 26.3 (or delete it).
Xcode can be updated from the App Store.Root Cause#
It is refusing to proceed because the active Xcode/Developer tools it sees are too old for current Homebrew requirements. Homebrew does enforce minimum Xcode / Command Line Tools versions, and when they are outdated it stops installs.
Even if a newer Xcode is installed, xcode-select is set to the old Xcode developer directory — the Command Line Tools are stale.
The Fix#
Try this in order.
# Show which Xcode/Developer tools path is currently selected on this Mac
xcode-select -p
# Check whether /Applications/Xcode.app exists and whether it is a real app folder or a link to another Xcode
ls -ld /Applications/Xcode.app
# List all Xcode apps in /Applications so you can see which versions are installed
ls /Applications | grep XcodeThen, if you do have a newer Xcode installed, switch to it explicitly:
sudo xcode-select -s /Applications/Xcode.app/Contents/DeveloperIf your real app is not /Applications/Xcode.app, point at the actual one, for example:
sudo xcode-select -s /Applications/Xcode_26.3.app/Contents/DeveloperAlso check the CLI tools:
# Show the installed version/details of Apple's Command Line Tools package
pkgutil --pkg-info=com.apple.pkg.CLTools_ExecutablesIf Command Line Tools are outdated, Homebrew’s usual fix is to reinstall them: remove the old CLT directory and run the installer again. That is the standard remedy Homebrew points people to when tools are too old.
# Delete the current Command Line Tools so they can be cleanly reinstalled
sudo rm -rf /Library/Developer/CommandLineTools
# Open Apple's installer prompt to download and install the latest Command Line Tools
xcode-select --installAfter that:
# Accept the Xcode license agreement from terminal so build tools can run without blocking
sudo xcodebuild -license accept
# Refresh Homebrew metadata and formula definitions to the latest version
brew update
# Run Homebrew diagnostics to detect common setup problems on your machine
brew doctorSummary#
If Homebrew blocks an install with a “too outdated” Xcode error, point xcode-select at your newest Xcode, reinstall Command Line Tools if needed, then re-run brew update && brew doctor.