"Sparkle can't be updated" error

If you are running a version of Sparkle from our website, an attempt to update it might result in this error:

Sparkle can’t be updated, because it was opened from a read-only or a temporary location. Use Finder to copy Sparkle to the Applications folder, relaunch it from there, and try again.

The root cause of the error is a quarantine state for the Sparkle app on that particular Mac. Quarantining apps originates in an earlier macOS version, where to fix an obscure security bug, Apple made all downloaded zip apps quarantined.

When in the quarantined state, apps launch in a read only disk image from a random location on disk, this solves the security issue.

Apps don’t generally need to write to their own path, except in the case of auto-updates of course.

The quarantine state is supposed to be lifted by the Finder, when you move the app out of the Downloads folder and drop it (usually) into the Applications folder. Unfortunately the Finder doesn’t do this 100% reliably, and in some cases the quarantine state is preserved even after the move.

So if you encounter this error you can:

  1. move Sparkle out of the Downloads folder
  2. if it has already been moved, move it back to the Downloads folder and again out
  3. if the update still doesn’t work, delete Sparkle and download a fresh copy from our site: https://sparkleapp.com/download