I believe the easy way to build an OMLx package from our GH sources is:
$ git clone https://github.com/OpenMandrivaAssociation/package_name.git
$ cd <name of package>
In this directory you can make any changes or add patches is you wish. Or just build with:
$ abb build
terminator will install in Cooker so if it does not install in ROME it probably just needs a rebuild for some dependency. Edit: I am looking in to this and will probably start a rebuild soon.
Note: An alternative build command using abf is:
$ abf rpmbuild
ABF=Automated Build Farm There are docs for ABF here and here. As far as I know abb build and abf rpmbuild do the same thing.
All the contributors and developers here are unpaid volunteers.
You are welcome to talk to our developers at OpenMandriva Chat.