gedit 40.0 not buildable - missing release of tepl-6
Gedit has not seen any of the 40.alpha/beta/rc release, but jumped from 3.38.1 straight to 40.0 - so there was no chance for distro packages to identify issue like this earlier.
gedit 40.0 has been released with a changed dependency from tepl-5 to tepl-6; tepl, otoh, has not have any more recent releases post 5.0.1 - which in turn means distros can't package/ship gedit 40 (unless packaging git snapshots of tepl).
Doing such jumps in a 'final/stable', without alpha/beta/rc puts distro packagers on a bad spot: simply updating tepl possibly might not work, as other things in the distro might not be ready for tepl-6; getting this all as part of 'a stable release' means there is no time for distros to actually adjust