Hey,
I don't want to pick a side in the turnstile-or-not fight, so I
found something you seemed to agree on, to disagree with:

Paul Sopka schrob:
> > [...] and unless you want to make users replace their shell with
> > something like `/etc/execline-startup` as described in
> > https://skarnet.org/lists/supervision/3126.html, your proposal is going
> > to need a custom PAM module for that too.
> [...]
> My proposal [...]
> by a potential pam module that exports it's content to the users shell.

There's already pam_env to set environment variables. And from
pam_env.conf it can expand @{HOME} and presumably ${USER}, which should
be all you need to accomodate desktop stuff that expects XDG_* and
DBUS_SESSION_BUS_ADDRESS.
Everything else can and should be done via conventional places in the
file system, the way DJB intended. ;)

cheers,
    Jan