SDLMAME 0.126 is finally packaged.
I'm sorry, I was at first on vacation, and since I returned I've been really busy.
A short note:
Like in baseline and upstream, from now on the debugger will be always built-in, and can be accessed with both configuration and line options (see manpage for further info).
However, GTK+ refuses to run a program in debugging mode when it's setuid, and sdlmame happens to be setuid to save configurations, states etc in proper directories.
If you can't wait to see the debugger in action, first of all you must chmod sdlmame executable to remove setuid.
This may sound bad, however consider that the debugger is only useful for Mame developers. It's NOT needed to play the games, it also speeds emulation down indeed. To cut it short: if you don't need it, forget about it.
You can download packages
from the usual place.
Enjoy!