Dear Guillermo,

Thanks for your reply.

On Tue, 26 Jul 2016 15:19:59 +0200
Guillermo Rodriguez Garcia <guille.rodriguez@gmail.com> wrote:

> Wouldn't it be easier to either use a custom /etc/passwd, or create a /root
> dir in the filesystem ? That sounds better than patching systemd.

Maybe it would be better to change the default /etc/passwd (and everywhere
else) in ptxdist then...

The problem is that what /etc/passwd says is mandatory. The home directory has
a special meaning to the user. You can get to the home directory via $HOME
passed in the environment, or via the NS-switch (getent) lookup. They are
supposed to be the same.
systemd has hardcoded defaults in source-code, which by definition is ugly as
hell, but the reason is clearly to avoid potentially expensive, blocking
NSS-lookups in the early boot stages, so it is understandable. It would be a
lot better if there was some configuration setting read from a file I guess,
but alas.
On PTXdist now (with the default, shipped /etc/passwd), a user logging in as
"root" via, say a serial console getty, will have a different $HOME than a
systemd service started with User=root. This is bad, and can potentially do
funny things people will not like.
To solve the problem, there are really only two options AFAICS:

 1.- Change PTXdist and all places in it that assume the $HOME=/home for root.
 No idea how many places that are, nor how many users already depend on this
 historic assumption.

or

 2.- Patch systemd to adapt to the reality of PTXdist.