On Tue, Jun 28, 2011 at 02:05:05AM +0200, Vincent Lefevre wrote: > > > http://gcc.gnu.org/ml/gcc-help/2010-11/msg00341.html
> > This particular issue will not occur with multiarch, because /usr/lib/<arch> > > will never be a symlink to /usr/lib in the canonical implementation. > There will be the same issue if libraries are installed directly > in /usr/lib/<arch> (see below). No, it's not the *same* issue. The issue you referenced is /usr/lib taking precedence over /usr/local/lib because of /usr/lib64 being a symlink. In multiarch, /usr/local/lib still takes precedence over /usr/lib. */usr/lib/$arch* might take precedence over /usr/local/lib, and that's not desirable, but it's not the same issue. > > As a practical matter, the runtime path will list all of the multiarch paths > > before all of the non-multiarch paths. > Like what upstream GCC does. So, this means that if I have LIBRARY_PATH > (and LD_LIBRARY_PATH) containing $HOME/lib, the library search path > would be something like: > $HOME/lib/<arch> > /usr/local/lib/<arch> > /lib/<arch> > /usr/lib/<arch> > $HOME/lib > /usr/local/lib > /lib > /usr/lib Huh? Certainly not. Why would you expect gcc to look in $HOME/lib/<arch> if you haven't put $HOME/lib/<arch> in your LIBRARY_PATH? gcc isn't going to magically append the architecture to all directories in the search path. with LIBRARY_PATH=$HOME/lib, the build-time order would (currently) be: $HOME/lib /usr/x86_64-linux-gnu/lib /usr/lib/x86_64-linux-gnu /lib /usr/lib (via: gcc -print-search-dirs | sed -n -e's/^libraries: =//p' | sed -e's/:/\n/g' | xargs -n1 readlink -f) So at build time, there doesn't appear to be an issue. > > (It does this already today.) > No, it doesn't. Well, it may depend on the tool, but for instance, > with the dynamic linker, the search order is: > prefix1/lib/<arch> > prefix1/lib > prefix2/lib/<arch> > prefix2/lib > prefix3/lib/<arch> > prefix3/lib > instead of: > prefix1/lib/<arch> > prefix2/lib/<arch> > prefix3/lib/<arch> > prefix1/lib > prefix2/lib > prefix3/lib > (according to strace). I think this is the right solution to avoid > the problem mentioned above. Ok - I didn't think we had this right, but it's great to know that we do. -- Steve Langasek Give me a lever long enough and a Free OS Debian Developer to set it on, and I can move the world. Ubuntu Developer http://www.debian.org/ slanga...@ubuntu.com vor...@debian.org
signature.asc
Description: Digital signature
