Hi,
As in ticket #413, I am trying to build libSBML (5.12.0 this time) using C++ 11 on Ubuntu 12.04 LTS, and I am still having problems with isnan(). I replaced the two calls (lines 1732 and 1741) with std::isnan() and now everything builds fine. HTH,
Alan
Thanks for letting us know, this is finally fixed in trunk and will be part of the next release.
Apologies that this got missed. It is now definitely in the code source.