Thanks for the post---lots of users found it very informative.
Unfortunately, GTG is broken in F28 and cannot be installed. Upstream
has been inactive for 3 years so the package should've been retired
before, but it slipped under my radar somehow.
I've retired it now, but one cannot retire packages from stable
branches, so it'll remain there until F28 goes EOL. I don't have n F27
system so I don't know if it can be installed on F27 either.
Users have already been running into the error when they try to install
gtg, so should anything be done about this? I've added a note to the bug
summary, so others that run into the issue can be made aware.
Sorry about this.
Ankur Sinha "FranciscoD"