[Mailman-Users] Frustration with set-gid

[Jeff Rush]

I'm wrestling with getting $prefix/mail/mailman to run as user 'mailman'
under Gentoo Linux and can't see what I'm doing wrong.

When running it manually (for debugging my setup):

  # mail/mailman post dfwPython
  Group mismatch error.  Mailman expected the mail
  wrapper script to be executed as group "mailman", but
  the system's mail server executed the mail script as
  group "root".

  # bin/check_perms
  No problems found

The executable in question has permissions/ownership:

  # ls -l mail/
  total 12
  -r-xr-sr-x 1 root mailman 9664 2010-04-13 23:56 mailman

and I wrote a tiny C pgm that just prints out the real/eff uid/gid as a
sanity check.  It has the exact same permissions/ownership:

  # ls -l printid
  -r-xr-sr-x 1 root mailman 7106 2010-04-14 08:13 printid

  # ./printid
  Real      UID = 0
  Effective UID = 0
  Real      GID = 0
  Effective GID = 280

where 280 is the correct GID for group 'mailman', so the set-gid
mechanism is working, just not with the mail/mailman executable.

This is with mailman-2.1.13 under Linux 2.6.31.

What am I overlooking?  The mailman package is built from the standard
Gentoo Linux distribution, not something I cobbled together.

-Jeff