It’s xcrun not scrum… but some people will say both are not good things to come across in life. 😛

Well, after you update your Mac OS this error may show up when you try to use git:

xcrun: error: invalid active developer path (/Library/Developer/CommandLineTools), missing xcrun at: /Library/Developer/CommandLineTools/usr/bin/xcrun

The way to solve this problem is to run the command to install command line tools:

xcode-select --install

-- Daniel Wildt