I'd imagine.
More focused on getting a working client out there than merged mining, for now. That'll come later. Really just need the blockchain before I can do any serious work on this.
You have to have the merged mining, the difference between being able to be merged mined as a secondary chain and not being able to be merged mined as a secondary chain is a breaking change, when first adding merged mining to a coin you need to schedule in advance a block number at which merged mining will be enabled, the blocks are different from there onward.
If you wanted to fork off a variant that no longer can be merged mined as a secondary chain you'd need to do the same, schedule a block number at which the block format that enables secondary chain ability is replaced with the old format the blocks used to have back before the merged mining was started.
So basically to base off of bitcoin you need a copy of bitcoin to which the merged-mining.patch has been applied. To base off some other coin you'd need to base it off of a coin that already has the ability to be merged mined as a secondary chain.
This is not a change a few constants "sed -i -e 's/bitcoin/scamcoin/g' -e 's/Bitcoin/Scamcoin/g' *" type of job, unless some existing coin that already can be secondary chain in a merge has already been updated to the version of bitcoin you are trying to update to...
-MarkM-
EDIT: I am uploading doti0coin.tgz to
https://sourceforge.net/projects/galacticmilieu/files/ it will take a while as it IS large, but it includes everything so should just need download time, no CPU overhead nor the database overhead of building indexes and so on. It won't show on the page until the upload completes. It contains a dir called doti0coin, not .i0coin, so untarring it won't walk over any existing .i0coin dir