Re: rtld or lang/gcc cannot find libgcc_s.so.1

On Tue, Feb 21, 2012 at 08:57:54PM +0200, Konstantin Belousov wrote:
> On Tue, Feb 21, 2012 at 10:28:50AM -0800, Steve Kargl wrote:
> > 
> > troutmask:kargl[210] halfspace
> > /lib/libgcc_s.so.1: version GCC_4.6.0 required by /home/kargl/bin/halfspace
> >  not foundtroutmask:kargl[211]
> > 
> > (Note, the annoying absense of a newline character after the error
> > message, which is a completely different issue.)
> > 
> > I see this problem on both freebsd-i386 and freebsd-amd64.
> > 
> > troutmask:kargl[212] ldd ~/bin/halfspace
> > /home/kargl/bin/halfspace:
> >         liblapack.so.4 => /usr/local/lib/liblapack.so.4 (0x2008c3000)
> >         libblas.so.2 => /usr/local/lib/libblas.so.2 (0x201463000)
> >         libgfortran.so.3 => /usr/local/lib/gcc46/libgfortran.so.3 (0x20175d000)
> >         libm.so.5 => /lib/libm.so.5 (0x201a70000)
> >         libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x201c95000)
> >         libquadmath.so.0 => /usr/local/lib/gcc46/libquadmath.so.0 (0x201ea2000)
> >         libc.so.7 => /lib/libc.so.7 (0x2020d6000)
> > troutmask:kargl[212] ldconfig -r | grep libgcc_s
> >         29:-lgcc_s.1 => /lib/libgcc_s.so.1
> >         723:-lgcc_s.1 => /usr/local/lib/gcc46/libgcc_s.so.1
> > 
> > So, it appears that rtld is finding the wrong libgcc_s.so.1 or 
> > the lang/gcc port is no longer providing sufficient information
> > for rtld to choose the correct library.
> > 
> > I have reverted revisions 230784, 299768, and 229508 (and
> > various combinitions of these revisions) from rtld-elf.  The
> > result does not change the above error.
> > 
> > I can work around the problem by specifying -static during
> > the building of my programs.  Or, I can work around the
> > problem by *explicitly* adding '-rpath /usr/local/lib' to the
> > command line, which I have never had to do.
> > 
> I highly suspect that you just happen to not need a symbol from the
> newest namespace before.
> 
> The thing to look first is the library search path in the ld.so hints,
> which is output at the second line of ldconfig -r. I think that you have
> /lib before /usr/local/lib/gcc46 in your setup. This guess is confirmed
> by the numeration of the two instances of gcc_s above. Either change
> the config, or use -rpath. AFAIR, ldconfig -m adds the directory
> at the end of the search list.

Yes, /lib comes before /usr/local/lib/gcc46.  I suppose
that this is a heads up for gerald_at_. lang/gcc is used by
the ports collections to build a large number of other
ports, so others are likely to hit this issue.

I tried reading rtld.c to see where the issue lies.  One
possibility seems to be a change in rtld.c (lines 4012-13)
to remember the version mismatch, then continuing the search 
to see if another library with the same name but different
location matches.  After exhausting the list of directories
in the search path, either an error is reported or a match
has been found.  Note, I'm still trying to parse and understand
the rtld.c code, so may be what I'm suggesting is not 
feasible.

-- 
Steve