Not ready for a new build but 6.7a is checked in with support for the Hanimex Pencil II. This super-obscure Australian console gone largely unnoticed until 2019 when one of the rare games got dumped: Treasure Hunter. It's a fun game - and one that would have been right at home on the venerable Colecovision back in the day.
To play it, you will have to jump through some hoops.
First you need a Pencil II BIOS. In MAME, the pencil2.zip file contains a number of ROM chips... the one you want is mt.u4 (8k) and this must be renamed to pencil2.rom and placed in your BIOS folder.
Second, you need the game. Which, unfortunately, came on 2 ROM chips. So you have to "glue" the two ROMs together. If you can find a late MAME "Software List" from 2020 or later, you will find treasure.zip which contains two ROM files:
pen702a.bin (8k)
pen702b.bin (4k)
You need to glue these together. In windows use the command line:
copy /b pen702a.bin + pen702b.bin TreasureHunt.pen
in Linux:
cat pen702a.bin pen702b.bin > TreasureHunt.pen
This should leave you with a 12k ROM called TreasureHunt.pen which is now playable on your ColecoDS system!
I'll be shocked if anyone other than me gets this game to run... but your effort will allow you to play one of the most rare and obscure games of any retro system!