Forcing any version of Xcode on VSTS Mac build agent

Developers using the Apple Store might have recently noticed a message indiciating that “This app has been built for iOS 11.x. Starting March 2019, all apps will be required to target iOS 12.1 available in Xcode 10.1”

DISCLAIMER: We haven’t yet had the opportunity to submit to the store to see if it accepts it, but the builds now work targetting the higher version.

Normally this is fine, just upgrade Xcode and rebuild. Not so obvious for VSTS (ADOPS?) and Cordova.
Surely Microsoft would just have the latest installed right?
Hmm, well kind of. If you look at the Mac build agent details, there’s versions of ALL major Xcode builds, it’s just that 8.x is set as default.

The many versions of Xcode supported by VSTS Mac build agent

Hmm, well maybe there’s a build step to set the default version of Xcode for this session?
Not that I could find.

We need to set the version for Cordova, but Cordova doesn’t provide an obvious way of setting the desired Xcode version, and there’s a caveat in the way they do provide. Turns out (after a bunch of googling) that you can set the path where Xcode is found.

And on the command line:

echo Current Xcode version:
xcode-select --print-path

echo Selecting Xcode version 10.1
sudo xcode-select -switch /Applications/Xcode_10.1.app/Contents/Developer

echo New Xcode version:
xcode-select --print-path

Below shows the area in the VSTS Cordova build step to add. Remember that the VSTS Mac build agent has all lots of versions, and changing the version number seems to correctly target the version specified.