Re: PATCH: honour DESTDIR

[Hans-Bernhard Broeker]

Alfred M. Szmidt <address@hidden> wrote:
> * Miles Bader writes:
>> "Federico G. Schwindt" <address@hidden> writes:
>>> Ok, this seemed pretty clear, and it's in your standards, but I want
>>> this to be able to change final destinations by seting DESTDIR, useful for
>>> cross-compiling by instance or to test snapshots in a pseudo real-world
>>> installation.

>> With most GNU software it's usually pretty easy to do this anyway, by
>> installing in a separate pass (from building), with `make prefix=...'.

> And most GNU software will become broken if you use `make prefix=...'
> as it can write some things that depend on `prefix', and if you change
> it to something that will be written into the binary. 

That's not really true.  At least not for "most" GNU software.  It's a
violation of GNU standards, AFAIK, to create any files from scratch in
a "make install" run after a (successful) "make".  So no change to
prefix only done for the "make install" run is allowed to affect the
_contents_ of the files actually installed.  Only their positions are
supposed to be affected.

> DESTDIR doesn't do this.

AFAICS, it quite certainly does.  If DESTDIR is set, it installs files
in a different place than 'make' believed them to be.  This will break
any hard-coded paths exactly as much or as little as 'make install
prefix=...' would.

The only real difference between DESTDIR and 'make install prefix=...'
I can see is that using DESTDIR you don't have to know the value of
$(prefix) as determined at ./configure time.  Other than that,

        ./configure prefix=/bar
        make 
        make install DESTDIR=/foo
        
is exactly equivalent to
        
        ./configure prefix=/bar
        make
        make install prefix=/foo/bar

which works nicely with almost every autoconf-governed package I've
tried in a long while.  I'm using the "stow" program to maintain may
/usr/local tree, which relies on this.  So I would have noticed if the
majority of program failed to get this right.
-- 
Hans-Bernhard Broeker (address@hidden)
Even if all the snow were burnt, ashes would remain.