First off, thanks a lot for replying, guys!
I can't wait to restore things when I get back to my machine monday.

Quoting "Perry E. Metzger" <perry@piermont.com>:
> "Michael G. Schabert" <mikeride@prez.org> writes:
> > At 11:46 AM +0000 3/27/03, airhead@vhe-382807.sshn.net wrote:
> > >./build.sh -U -D /usr/dist -E distribution
> > >./build.sh -D /usr/dist -U install=/
> > 
> > Hi Peter,
> > You *MUST* be root when you do that second line. The unprived mode
> > lets you not be root during BUILDING, but to do the actual install
> > requires root since regular users cannot make a binary be SUID root
> > (as you noticed).

It isn't possible that I did this wrong anyway, since su was not writable by anyone but root.
So that could not have done it, since I haven't touched the su binary in any way and I do think my initial install's permissions were correct.
It also seems quite impossible to have root own the file and me not having write access to it after the install. You can't chmod a file you don't own, am I correct? And after the install I didn't have write access to /bin/su at all.
I think something else went wrong.

> One also wonders at the use of -E.
> 
> Using -E is dangerous and unneeded here. It is the equivalent of
> aiming a loaded gun at your foot.

ROFL. I'm not sure why I did this. I think it was because of the missing entry an.phones or something like that. See my previous post about that.
I was trying if it would install when I did -E, but it didn't. Probably I simply did a !-5 or something similar to run the command again after adding that file to the list.

Could this flag have mangled the installation permissions somehow? Doesn't seem logical either.

Anyway, we'll see what happens if I do a new installation on monday.

Regards,
Peter
---
"The process of preparing programs for a digital computer
is especially attractive, not only because it can be economically
and scientifically rewarding, but also because it can be an aesthetic
experience much like composing poetry or music."
        --Donald Knuth