Difference between ROOT_USER and REAL_ROOT_USER

[Roland Illig <roland.illig%gmx.de@localhost>]

Hi,

I'd like to know the difference between ROOT_USER and REAL_ROOT_USER. I
looked in mk/**, the pkgsrc guide and the pkglint source code, but none
of these places explains what these two variables are used for.

Am I guessing right that ROOT_USER should better be called SU_USER, and
if that were done, REAL_ROOT_USER could be renamed to ROOT_USER?

I need this information because right now pkglint cannot explain why
REAL_ROOT_USER must be used in *_PERMS variables and ROOT_USER must not
be used there.

Best,
Roland