Re: GNU Libtool 2.4 released [stable]

[Charles Wilson]

On 10/1/2010 2:23 AM, Alon Bar-Lev wrote:
> I wanted to see the process this way...
> 
> export SYSROOT=/tmp/root1
> 
> package1: ./configure
> package1: make install DESTDIR=/tmp/root1
> 
> package2: ./configure
> package2: make install DESTDIR=/tmp/root2

What you are missing is that "sysroot" is primarily something associated
with cross-compilers, not native compilers (so your "configure" would
need a "--host=something --build=somethingelse").

Also, it's something that is understood by the compiler and binutils you
are using.  Even if libtool were to use an env variable as you suggest,
the most likely setting would be:

SYSROOT=`i686-pc-mingw32-gcc -print-sysroot`
         ^^^^^^^^^^^^^^^^^^^
         cross compiler name

But...if the "correct" sysroot can be detected from the compiler, why
explicitly pass the value in the first place?  Why not just tell libtool
to grab the value from the compiler, itself?  Using something like...
--with-sysroot.   (Note that --with-sysroot=/some/path is merely a
mechanism to allow overriding the detected sysroot in odd cases; typical
use would be --with-sysroot without a path argument).


Also, the "DESTDIR" differs from sysroot, in that on the cross compiler
build system, you would actually install the compiled product INTO the
sysroot *permanently* -- to support building and linking against it when
cross-compiling additional packages.  It's not "temporary" in any way.
(If you were creating a cross-compiled package that somebody else would
install as part of a cross-compiling SDK -- think Fedora's mingw
packages -- then you might use both sysroot *and* DESTDIR).

--prefix, sysroot, and DESTDIR serve different purposes.

Please, over the past three months there were hundreds of messages
discussing sysroot and how it shoold be handled.  While libtool's
support is not yet complete, what IS there is the result of those
discussions.  Please read them; I have a suspicion you don't quite grok
what sysroot is really FOR, so your assumptions about how it
should/shouldn't/does/doesn't work are somewhat flawed.

--
Chuck