Re: Core-utils 7.2; building only 'su'

[Ralf Wildenhues]

Hello Alfred, Eric,

* Alfred M. Szmidt wrote on Tue, Apr 14, 2009 at 02:49:30PM CEST:
>    >    Hmmm.  Would it be worth changing autoconf to make './configure
>    >    --help' state something like the following:
>    > 
>    >    | Some influential environment variables:
>    >    |   ...
>    >    |   DESTDIR    leave unset during configure; allows installation to
>    >    |              specify a staging area different than the final prefix

Please, let's not bloat `configure --help' output even more.  It is
already very long for a simple help text, it should not document things
that are not, in fact, settings for configure but for the makefile.

>    Not all packages follow GNU Coding Standards, therefore, DESTDIR is not
>    properly supported in a surprisingly large number of packages.
> 
> We already enforce a level of GNUism on packages that use
> autoconf/automake, I do not think it would be the end of the world if
> we did it in this case as well.

This case is different.  DESTDIR has the important drawback that it does
not work well with w32-style installation directory names like `C:/foo',
because you cannot prepend to such a path.  So for maximum portability
you should support this in your package, too.  BTW, why do you state
that overriding just $prefix would be "almost always wrong"?

DESTDIR can still serve as a more convenient way to override several
installation directories at once (and it is necessary for a good
experience for packages using libtool).

And no, I don't like the idea of forcing more GNUisms, more so for
*optional* features (the GNU Coding Standards do not mandate DESTDIR
support).  That's what things like the Automake option `gnits' and
`make distcheck' are for, and they let you opt in to the pain.

>    > I do not think that users are confused about passing DESTDIR
>    > during configure time either.  DESTDIR is and has always been a
>    > automake variable.  Alas, the only useful place to put this
>    > information is in the output of --help.  Maybe something more
>    > like this would be a bit more suitable (not to happy about the
>    > actual wording):
>    > 
>    > `To install FOO in a different directory for the purpose of
>    > making a tarball, or similar pass DESTDIR to `make install''
> 
>    Maybe the shorter:
> 
>    `To install FOO in a staging directory, use `make install DESTDIR=...''
> 
> I like that.

However, this text may not be added by Autoconf as Autoconf cannot be
sure that the package supports this.  Pedantically, the package cannot
even be sure that `make' is used at all.  IMVHO the right place to
document DESTDIR is along with documentation to the standard make
targets.  INSTALL documents a couple, but would grow too large if it
documented all (and is also targeted at non-automake-using packages).

Maybe the generic INSTALL file should provide pointers to more
comprehensive documentation?

Cheers,
Ralf