The use in several parts of urdfdom of the function std::stod can be source of errors if the library is used together with other libraries (such as Qt) that change the system locale.
Slightly related, I assume (from all the ROS code using the library) the correct way of encoding floating point numbers as strings in the URDF file format is the one defined by the "C" standard locale, but this is not actually documented anywhere (see gbionics/idyntree#288 (comment)).
Downstream issue: gbionics/idyntree#288
Similar SDFormat issue: https://bitbucket.org/osrf/sdformat/issues/60