Comment 15 for bug 1248642

Hi Alberto,

One of our GL driver engineers looked into this a bit, and it actually seems to be a linker regression that is exposed when linking an application against the Mesa libGL, and then running it against the NVIDIA one. He is gathering some more information before filing a bug, but in the mean time, please find attached a test case demonstrating the linker bug, which doesn't involve either the Mesa libGL or the NVIDIA one. See the README in the tarball for details.

When bisecting binutils in an attempt to identify the regression, our engineer found that commit commit b64fb44af4f416fbbbda3de03fcfff61d80c841c ("Also track weak references") actually introduced a link time error when attempting to link the test executable:

ld: /tmp/cc3K1rHK.o: undefined reference to symbol 'pthread_create@@GLIBC_2.2.5'
ld: note: 'pthread_create@@GLIBC_2.2.5' is defined in DSO //lib/x86_64-linux-gnu/libpthread.so.0 so try adding it to the linker command line

That ld error no longer occurs after commit
879707c642925947e156b7ae2169b89f844532cd ("Exclude weak refs when considering whether an --as-needed library is needed"); however, the bug described here (assertion from ld.so) does.

We believe that this Debian bug may be related:

http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=728529