Re: problems with "make install" directory permissions

[Jim Meyering]

On Mon, Jul 27, 2020 at 3:03 PM Paul Eggert <eggert@cs.ucla.edu> wrote:
>
> On 7/27/20 2:24 PM, Karl Berry wrote:
> >      https://lists.gnu.org/r/bug-bison/2020-07/msg00042.html
> >
> > I can understand increasing permissions to allow +rx on installation
> > directories, but why force 755, thus disallowing group writability?
> > I've never understood this forcing of 755.
>
> I expect it was by analogy with regular files, where are already forced to use
> the equivalent of umask 22 when being installed.
>
> This could have been a decision I made years ago when modifying GNU 'install' 
> -
> I've forgotten the details. (No doubt it was a good decision at the time. :-)

>From what I recall, we deliberately avoid making installed things
group-writable because that would induce a security risk in
installations where more than one user is in the same default group.

If I install in such an environment (and don't override the group), I
don't want a peer to be able to modify what I've just installed.