I am having problems when I attempt to add a new Swift Package to my project.
On Xcode 11.3.1 I receive a "Couldn't communicate with a helper application." error message.
PS with Xcode 11.4 the error message has changed to "Communication with the service was interrupted."
Having looked in the console app I can see a com.apple.dt.Xcode.sourcecontrol.Git crash is occuring. I've uploaded the crash report here...
https://gist.github.com/OliverPearmain/0320f34d6381d1bb7900ff266fc8d703
I've finally worked out what this was. I had something in my ~/.gitconfig file which Xcode obviously did't like.
I worked this out by removing the ~/.gitconfig and then retrying (and it worked). Then I tried removing parts of the ~/.gitconfig contents bit by bit.
Evntually I idenitified that this was the section causing the issue.
[includeIf "gitdir:~/some/path/"]
path = "~/some/path/.gitconfig_include"
This section works in other contexts. No idea why it causes Xcode to barf.
In my case the issue was caused by empty email line in ~/.gitconfig.
Changing "email = " to "email = example.email.com" helped.
Had a stale entry in my ~/.gitconfig with difftool set to an app that I don't have now.
Removed the entry, reopened Xcode, problem gone.