today I've noticed that the problem described here is solved for gdb 7.7.1+dfsg-5 (which is the version currently in Debian/stable)
With this version, there is still a similar problem with std::function and lambda, when additionally an argument type uses a template parameter from the enclosing function https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=795445 this additional problem seems to be resolved with the next version from upstream though
