Possible bug when using logarithm in Expression

[Eldar Khattatov]

With Fenics 2018.1.0 installed with conda on macOS 10.13 there seems to be an issue with the following code:

from dolfin import *
expr = Expression("log(x[0])", degree=3)

It tries to use void log(int debug_level, std::string msg, ...); function instead of natural logarithm according to the compiler output (which is attached) and fails due to that.

Other math functions work fine, including log1p which can be used as a workaround for this issue.