Static libraries that are - compiled with dmd 2.074 (maybe previous versions too) - call format() in their API
will be responsible for strange errors when used by programs compiled with dmd 2.075. People will see their software raising a FormatException (orphan argument) for no reason. When the static library will be recompiled with dmd 2.075 the errors will disappear.
I haven't investigated much since there's been a non trivial amount of change in std.format() during the this spring. I don't know what to do with this facts except to report them here.