macOS blocks Homebrew portable Ruby 4.0.5_1 after Intego false-positive incident

[GilgameshTheBeaver]

Output of brew config

/opt/homebrew/bin/brew config
==> Downloading https://ghcr.io/v2/homebrew/core/portable-ruby/blobs/sha256:4ba8d535df01e4bf97e6661c3815796fd77364ea2552606e891659133a76f0e1
Already downloaded: /Users/REDACTED/Library/Caches/Homebrew/portable-ruby-4.0.5_1.arm64_big_sur.bottle.tar.gz
==> Pouring portable-ruby-4.0.5_1.arm64_big_sur.bottle.tar.gz
/opt/homebrew/Library/Homebrew/cmd/vendor-install.sh: line 258: 3160 Killed: 9 "./${VENDOR_VERSION}/bin/${VENDOR_NAME}" --version > /dev/null
Error: Failed to install ruby 4.0.5_1!
Error: Failed to install Homebrew Portable Ruby (and your system version is too old)!

Output of brew doctor

`brew doctor` cannot complete because Homebrew attempts to install/run portable Ruby 4.0.5_1 and macOS blocks it.

Observed output:

==> Downloading https://ghcr.io/v2/homebrew/core/portable-ruby/blobs/sha256:4ba8d535df01e4bf97e6661c3815796fd77364ea2552606e891659133a76f0e1
Already downloaded: /Users/REDACTED/Library/Caches/Homebrew/portable-ruby-4.0.5_1.arm64_big_sur.bottle.tar.gz
==> Pouring portable-ruby-4.0.5_1.arm64_big_sur.bottle.tar.gz
/opt/homebrew/Library/Homebrew/cmd/vendor-install.sh: line 258: ... Killed: 9 "./${VENDOR_VERSION}/bin/${VENDOR_NAME}" --version > /dev/null
Error: Failed to install ruby 4.0.5_1!
Error: Failed to install Homebrew Portable Ruby (and your system version is too old)!

Description of issue

Apple Silicon Mac running macOS 26.5.1 (25F80), Homebrew 6.0.2.

After an Intego detection involving Homebrew portable Ruby that was later cleared by updated definitions, I removed and re-created Homebrew portable Ruby. The current Intego scan of the portable-ruby folder is clean. However, macOS still blocks the recreated Homebrew portable Ruby.

/opt/homebrew/bin/brew update appears to complete successfully.

When brew doctor or brew config attempts to use portable Ruby 4.0.5_1, macOS shows:

“ruby” Not Opened
Apple could not verify “ruby” is free of malware that may harm your Mac or compromise your privacy.

The dialog offers only Move to Trash or Done.

Affected path:

/opt/homebrew/Library/Homebrew/vendor/portable-ruby/4.0.5_1/bin/ruby

I have not used xattr, disabled Gatekeeper, or manually modified Homebrew beyond removing the incomplete portable-ruby/4.0.5_1 folder and letting Homebrew recreate it.

I temporarily disabled shell startup lines that invoke brew, because opening a new Terminal window was repeatedly triggering the failed portable-Ruby install.

Is there a Homebrew-supported recovery path for this macOS/Gatekeeper block?

I prepared this report with AI assistance to organize the sequence and logs; the commands, outputs, and screenshots are from my machine.

[Bo98]

My guess is it added the quarantine attribute to ~/Library/Caches/Homebrew/portable-ruby-4.0.5_1.arm64_big_sur.bottle.tar.gz. You can either rm the file to try download it again or manually clear it with xattr -c.

[GilgameshTheBeaver]

That fixed it. I deleted only the cached portable-ruby archive, reran brew doctor, and Homebrew downloaded a fresh archive and completed successfully. The remaining output is only ordinary PATH/deprecation warnings. Thank you.