Am Samstag, 23. November 2013 schrieb Marguerite Su:
And /usr/lib/steam is also marked %ghost, but it is created and owned by steam package.
We write such things in %files section simply because we want the rpm to own all the things, the directories created in %install section, and the filled contents in %post section.
A maybe silly question - why don't you package those directories as %dir /usr/lib/steam if they are created in %post anyway (aka "always there")? That avoids the black magic and also cleans up when removing the package (only empty directories are removed AFAIK).
BTW: Directories can be owned by multiple packages without conflicts (the permissions should of course match ;-)