Research IT

Installing apps on macOS Catalina (10.15)

The top tip for March by Ian Cottam, Head of Research Software Engineering, looks at installing apps on macOS Catalina (10.15) that have not been authorised or certified by Apple.

Last year, Ian Hinder and I wrote about being cautious regarding updating from macOS 10.14 Mojave to 10.15 Catalina. Our main concern was the abandonment of 32-bit application support. However, a further concern has come to light, even with 64-bit software applications.

Apple has long had a wall-gardened approach to apps on its mobile platforms: iOS and iPadOS; this has now encroached on macOS with Catalina. By default Catalina will not allow you to install an application that they have not approved or certified. There are, still however, ways around their blockade.

Recently I tried to install Condor on someone's MacBook running Catalina. On Mojave I knew this was a trivial 3 minute job. Not so any more. Trying to run the installer from Terminal just gave me a popup saying did I want to delete this unknown app! Luckily, you can still say ‘Cancel’.

What to do? After much Googling, I came upon the advice to install Apple's Xcode, if not already installed. This is a massive application that Condor should not need, nevertheless I installed it from the App Store.

This then lets you go to System Preferences/ Security&Privacy / Privacy tab and click on "Developer Tools" in its left panel; then tick Terminal in the right one (you will probably need to click on the lock icon and enter your admin password). Let it kill Terminal if you have it open. What you have done is authorise Terminal to run apps not Apple certified.

This is not quite the end of the story, as the Condor start up code runs several background, support programs. These too are flagged by Catalina as somehow suspect and suggests you let it delete them. The way around this is to remove the attribute from such binary files that requests they be quarantined / deleted when run. You do this from Terminal, like so:

xattr -r -d com.apple.quarantine /path to dir where e.g. bin and sbin folders are

the -d means delete the named attribute and the -r means recursively down through the hierarchy of directories.

I found all this advice on this useful, external site, which reports on a similar experience with another Mac application. If this gets any more stringent in future releases of macOS, it might spell the end for Macs in academia and the research world.