I've got a 'HomeBrew' version of the latest installation script, that gets Lazarus installed and up and running on a clean El Capitan install. I'm going to try and merge it with the MacPorts one (shouldn't be rocket science, but I'm new to Bash scripts), and then perhaps try my first git pull request
In the meantime (before it appears anywhere 'official'), if anyone wants it just give me a nudge.
The one wrinkle I had was that gdb seems to be called gdb under MacPorts, it took me a while to realise that just installing gdb under 'Brew seemed to do the trick (and Lazarus out of the box spots it just fine). Everything is dead straightforward and almost exactly the same.
Oh, and the whole code signing 'theatre' remains the same, of course.