Suggestions for a "die on error" option to ttree?

I have a question about how one might use ttree.  I looked briefly in 
the archives and couldn't find much about ttree at all, so if I'm asking 
this question in the wrong place, please be so kind as to redirect me.

I'm using ttree as part of a build process, instantiating some files 
that are needed later one.  When I mess up and forget the make the 
correct directory writable, ttree prints warning messages but lets the 
process go ahead just fine.  I would prefer that it die.

Maybe there could be a command-line flag would change, say, the "red" or 
"yellow" method to include a "die" or something like that?  Sort of like 
the way they change if "--color" is set?

Thanks for your comments,

dave