macOS Ventura 13.3 alters expected behavior for Finder’s Open With functionality for macOS installer packages

I’m a frequent user of macOS’s Open With functionality, where I can control-click on a file and select what app I want to open the file with.

Among the files I’m used to doing this with are installer package files. However, I noticed that as of macOS 13.3, this mostly stopped working as the only choice I now had for installer packages was the Installer app. Here’s how it looks on macOS 13.2.1, on a Mac with the Suspicious Package application installed:

Here’s how it looks on macOS 13.3, on a Mac with the Suspicious Package application installed:

When I looked in a Get Info window for an installer package on macOS 13.3, the Open with: functionality was both grayed out and set to Installer.

Normally I would have suspected a bug in macOS 13.3, but according to Randy Saldinger of Mothers Ruin Software, this appears to be an undocumented change by Apple in macOS 13.3.

For more details, please see below the jump.

As of macOS 13.3, a new LaunchServices key in the CFBundleDocumentTypes dictionary, named LSIsAppleDefaultNoOverrideForType, appears to have been introduced. This new key so far only appears in the following file:

/System/Library/CoreServices/CoreTypes.bundle/Contents/Resources/Exceptions.plist

This key is applied to all three package document types used by the Installer app, which means it covers all known macOS installer package files (both flat packages and bundle-style packages.)

The new key appears to affect how LaunchServices manages the Open With functionality specifically in the context of installer packages.

There are still ways outside of the Open With functionality to open an installer package in a desired application. One of the ways is to use the open command in Terminal. For example, if you had an installer package named example.pkg stored on your desktop and you wanted to open the installer package in the Suspicious Package application, you could run the command below:

The Suspicious Package application should subsequently open and display information about the installer package you had specified.