Chris Halse Rogers investigated this and he has confirmed that this problem is actually due to longstanding bug 259219. The recent update of libgl1-mesa-glx to version 7.10.1-0ubuntu1 adds a dependency on libstdc++6, with the result that we are now seeing the effects of bug 259219 in software-center.
Per Chris' suggestion, this is confirmed by the fact that launching software-center as follows fixes the problem:
Chris Halse Rogers investigated this and he has confirmed that this problem is actually due to longstanding bug 259219. The recent update of libgl1-mesa-glx to version 7.10.1-0ubuntu1 adds a dependency on libstdc++6, with the result that we are now seeing the effects of bug 259219 in software-center.
Per Chris' suggestion, this is confirmed by the fact that launching software-center as follows fixes the problem:
LD_ PRELOAD= /usr/lib/ libstdc+ +.so.6 PYTHONPATH=. python ./software-center