I'm not sure about making this question here but I don't know where to do it.
I'm using cvs version of TikZ and from time to time I found it incompatible with some other packages based on its released version. Some time ago it happened with forest
(although I think it's solved) and today happened with tikzposter
and tikz-mimo-shapes. If I use pgf-2.1 everything works, but with cvs version some error stops compilation.
So, what to do know? With forest
I sent a message to the author and he provided me a patch which I think was later incorporated into a newer version.
Another option would be to fill a bug report in pgf's place explaining these problems.
An the last one would be to use or not cvs version depending on what package I'm using, but this one is not very comfortable.
What do you suggest?